🛡️ Sentinel: [HIGH] Fix file upload validation bypass#48
🛡️ Sentinel: [HIGH] Fix file upload validation bypass#48Krosebrook wants to merge 8 commits intomainfrom
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🚨 Severity: HIGH 💡 Vulnerability: The /api/audio/generate-with-reference endpoint relied solely on the client-provided MIME type (via Multer) to validate uploaded files. This allowed users to bypass validation by renaming malicious files (e.g., scripts, executables) with audio extensions. 🎯 Impact: Attackers could upload arbitrary files disguised as audio. While immediate RCE is mitigated by base64 encoding and external processing, this is a dangerous validation gap that could be exploited if file processing logic changes (e.g., local FFmpeg execution). 🔧 Fix: Implemented verifyAudioFileSignature in server/utils.ts to check the magic bytes (file signature) of uploaded files against known audio formats (MP3, WAV, OGG, FLAC, AAC/M4A). Updated the route handler to reject files with invalid signatures. ✅ Verification: Added comprehensive unit tests in server/utils.test.ts covering valid and invalid file signatures. Verified that valid audio files pass and invalid files (including text and executables) fail. Co-authored-by: Krosebrook <214532761+Krosebrook@users.noreply.github.com>
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Summary of ChangesHello @Krosebrook, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed! This pull request introduces a critical security enhancement by implementing server-side validation of audio file signatures. Previously, the system relied on client-provided MIME types, which could be easily manipulated to upload malicious files disguised as audio. The new validation mechanism inspects the actual file content, significantly reducing the risk of arbitrary file uploads and potential exploitation, thereby bolstering the application's security posture. Highlights
Changelog
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📝 WalkthroughWalkthroughAdded audio file signature validation: exported Changes
Sequence Diagram(s)sequenceDiagram
participant Client as Client
participant Server as Server
participant Utils as Utils
participant Processor as Processor
Client->>Server: POST /api/audio/generate-with-reference (multipart file)
Server->>Utils: verifyAudioFileSignature(file.buffer)
alt signature valid
Utils-->>Server: true
Server->>Processor: proceed with audio processing
Processor-->>Server: processing result
Server-->>Client: 200 + result
else signature invalid
Utils-->>Server: false
Server-->>Server: sanitizeLog({ userId, fileSize, mimeType, originalName })
Server-->>Client: 400 "Invalid file signature. Please upload a valid audio file."
end
Estimated code review effort🎯 3 (Moderate) | ⏱️ ~22 minutes Possibly related PRs
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🧪 Generate unit tests (beta)
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Code Review
This pull request effectively addresses a critical security vulnerability by implementing file signature validation for audio uploads, preventing malicious file uploads disguised as audio. The new verifyAudioFileSignature function is well-implemented and accompanied by a comprehensive set of unit tests that cover valid, invalid, and edge cases. The integration into the route handler is correct. I have one suggestion to improve the maintainability of the new validation function by refactoring the magic numbers into named constants. Overall, this is an excellent and important security enhancement.
| export function verifyAudioFileSignature(buffer: Buffer): boolean { | ||
| if (!buffer || buffer.length < 12) return false; | ||
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| const header = buffer.subarray(0, 12); | ||
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| // MP3: ID3v2 (49 44 33) or Sync Frame (FF FB / FF F3 / FF F2) | ||
| // Note: Sync frame usually starts at byte 0 for raw streams, but ID3 tag is common. | ||
| if ( | ||
| (header[0] === 0x49 && header[1] === 0x44 && header[2] === 0x33) || | ||
| (header[0] === 0xff && (header[1] === 0xfb || header[1] === 0xf3 || header[1] === 0xf2)) | ||
| ) { | ||
| return true; | ||
| } | ||
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| // WAV: RIFF (52 49 46 46) ... WAVE (57 41 56 45) | ||
| if ( | ||
| header[0] === 0x52 && | ||
| header[1] === 0x49 && | ||
| header[2] === 0x46 && | ||
| header[3] === 0x46 && | ||
| header[8] === 0x57 && | ||
| header[9] === 0x41 && | ||
| header[10] === 0x56 && | ||
| header[11] === 0x45 | ||
| ) { | ||
| return true; | ||
| } | ||
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| // OGG: OggS (4F 67 67 53) | ||
| if (header[0] === 0x4f && header[1] === 0x67 && header[2] === 0x67 && header[3] === 0x53) { | ||
| return true; | ||
| } | ||
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| // FLAC: fLaC (66 4C 61 43) | ||
| if (header[0] === 0x66 && header[1] === 0x4c && header[2] === 0x61 && header[3] === 0x43) { | ||
| return true; | ||
| } | ||
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| // AAC/M4A: ftyp (66 74 79 70) usually at offset 4 | ||
| if (header[4] === 0x66 && header[5] === 0x74 && header[6] === 0x79 && header[7] === 0x70) { | ||
| return true; | ||
| } | ||
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| // AAC ADTS: FF F1 (MPEG-4) or FF F9 (MPEG-2) | ||
| // Sync word is 12 bits of 1s (0xFFF) | ||
| if (header[0] === 0xff && (header[1] & 0xf0) === 0xf0) { | ||
| return true; | ||
| } | ||
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| return false; | ||
| } |
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The function verifyAudioFileSignature is well-structured and covers many important audio formats. However, it uses many "magic numbers" directly in the if conditions, which can make the code harder to read and maintain.
To improve clarity and maintainability, I suggest refactoring this function to use named constants for the magic byte sequences and Buffer.equals() for comparisons. This makes the purpose of each check more explicit and the code more idiomatic. The SIGNATURES object is defined inside the function for a self-contained suggestion, but could be moved to the module scope for a minor performance gain.
export function verifyAudioFileSignature(buffer: Buffer): boolean {
if (!buffer || buffer.length < 12) return false;
const header = buffer.subarray(0, 12);
const SIGNATURES = {
ID3: Buffer.from([0x49, 0x44, 0x33]),
RIFF: Buffer.from([0x52, 0x49, 0x46, 0x46]),
WAVE: Buffer.from([0x57, 0x41, 0x56, 0x45]),
OGG: Buffer.from([0x4F, 0x67, 0x67, 0x53]),
FLAC: Buffer.from([0x66, 0x4C, 0x61, 0x43]),
FTYP: Buffer.from([0x66, 0x74, 0x79, 0x70]),
};
// MP3: ID3v2 tag or Sync Frame. A more general check for MPEG frames is used.
const isMp3 =
header.subarray(0, 3).equals(SIGNATURES.ID3) ||
(header[0] === 0xff && (header[1] & 0xe0) === 0xe0);
// WAV: RIFF header with WAVE format
const isWav =
header.subarray(0, 4).equals(SIGNATURES.RIFF) &&
header.subarray(8, 12).equals(SIGNATURES.WAVE);
// OGG: OggS capture pattern
const isOgg = header.subarray(0, 4).equals(SIGNATURES.OGG);
// FLAC: fLaC marker
const isFlac = header.subarray(0, 4).equals(SIGNATURES.FLAC);
// M4A/MP4: ftyp box at offset 4
const isM4a = header.subarray(4, 8).equals(SIGNATURES.FTYP);
// AAC ADTS: Sync word (12 bits of 1s)
const isAacAdts = header[0] === 0xff && (header[1] & 0xf0) === 0xf0;
return isMp3 || isWav || isOgg || isFlac || isM4a || isAacAdts;
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server/utils.ts
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| if (header[0] === 0xff && (header[1] & 0xf0) === 0xf0) { | ||
| return true; |
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This condition accepts any payload starting with 0xFF followed by any byte whose high nibble is 0xF, which is much broader than a valid AAC ADTS header. A non-audio file can be prefixed with FF F0 and will pass verifyAudioFileSignature, so /api/audio/generate-with-reference can still accept forged uploads despite the new guard.
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server/utils.ts
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| if (header[4] === 0x66 && header[5] === 0x74 && header[6] === 0x79 && header[7] === 0x70) { | ||
| return true; |
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Checking only for ftyp at offset 4 treats any ISO-BMFF file as valid audio, including ordinary MP4 video files and other non-audio container types that share this marker. Because this branch returns true without verifying an audio brand (for example M4A ) or other audio-specific fields, non-audio uploads can still pass the new validation path.
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Pull request overview
This PR addresses a HIGH severity security vulnerability in the /api/audio/generate-with-reference endpoint where file upload validation relied solely on client-provided MIME types, allowing attackers to bypass validation by renaming malicious files with audio extensions. The fix implements magic byte (file signature) verification to ensure uploaded files are genuinely audio files.
Changes:
- Added
verifyAudioFileSignature()function to validate file signatures for MP3, WAV, OGG, FLAC, and AAC/M4A formats - Integrated signature verification into the file upload endpoint before processing
- Added comprehensive unit tests for valid/invalid file signatures
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 8 comments.
| File | Description |
|---|---|
| server/utils.ts | Implements magic byte validation for audio file signatures (MP3, WAV, OGG, FLAC, M4A, AAC) |
| server/utils.test.ts | Adds test coverage for file signature validation including valid audio formats and invalid files |
| server/routes.ts | Integrates signature verification into the upload endpoint to reject files with invalid signatures |
| /** | ||
| * Sentinel 🛡️: Validates audio file signatures to prevent malicious uploads. | ||
| * Checks for MP3, WAV, OGG, FLAC, and AAC/M4A magic bytes. |
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The comment uses "Sentinel 🛡️:" as a branded prefix, which violates the coding guidelines. According to the project guidelines, comments should not use branded prefixes. Remove the "Sentinel 🛡️:" prefix and use a simple descriptive comment instead, such as "Validates audio file signatures to prevent malicious uploads."
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@copilot open a new pull request to apply changes based on this feedback
server/routes.ts
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| // Sentinel: Verify file signature (magic bytes) | ||
| if (!verifyAudioFileSignature(file.buffer)) { |
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The comment uses "Sentinel:" as a branded prefix, which violates the coding guidelines. According to the project guidelines, comments should not use branded prefixes. Remove "Sentinel:" and simply say "Verify file signature (magic bytes)" or just use the existing comment from the function definition.
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@copilot open a new pull request to apply changes based on this feedback
server/utils.ts
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| // MP3: ID3v2 (49 44 33) or Sync Frame (FF FB / FF F3 / FF F2) | ||
| // Note: Sync frame usually starts at byte 0 for raw streams, but ID3 tag is common. | ||
| if ( | ||
| (header[0] === 0x49 && header[1] === 0x44 && header[2] === 0x33) || | ||
| (header[0] === 0xff && (header[1] === 0xfb || header[1] === 0xf3 || header[1] === 0xf2)) |
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The MP3 sync frame check only validates 0xFF followed by 0xFB, 0xF3, or 0xF2. However, MP3 sync frames can also use 0xFA, 0xE2, and 0xE3 depending on the MPEG version and layer. While the most common patterns are covered, this could reject some valid MP3 files. Consider expanding the check to include all valid MP3 sync patterns: for MPEG-1 Layer III use 0xFF 0xFB/0xFA, for MPEG-2 Layer III use 0xFF 0xF3/0xF2, and for MPEG-2.5 Layer III use 0xFF 0xE3/0xE2. However, be cautious about being too permissive.
| // MP3: ID3v2 (49 44 33) or Sync Frame (FF FB / FF F3 / FF F2) | |
| // Note: Sync frame usually starts at byte 0 for raw streams, but ID3 tag is common. | |
| if ( | |
| (header[0] === 0x49 && header[1] === 0x44 && header[2] === 0x33) || | |
| (header[0] === 0xff && (header[1] === 0xfb || header[1] === 0xf3 || header[1] === 0xf2)) | |
| // MP3: ID3v2 (49 44 33) or sync frame: | |
| // - MPEG-1 Layer III: FF FB / FF FA | |
| // - MPEG-2 Layer III: FF F3 / FF F2 | |
| // - MPEG-2.5 Layer III: FF E3 / FF E2 | |
| // Note: Sync frame usually starts at byte 0 for raw streams, but ID3 tag is common. | |
| if ( | |
| (header[0] === 0x49 && header[1] === 0x44 && header[2] === 0x33) || | |
| (header[0] === 0xff && | |
| (header[1] === 0xfb || | |
| header[1] === 0xfa || | |
| header[1] === 0xf3 || | |
| header[1] === 0xf2 || | |
| header[1] === 0xe3 || | |
| header[1] === 0xe2)) |
server/routes.ts
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| // Sentinel: Verify file signature (magic bytes) | ||
| if (!verifyAudioFileSignature(file.buffer)) { | ||
| return res.status(400).json({ message: "Invalid file signature. Please upload a valid audio file." }); | ||
| } |
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Security-critical validation failures (like file signature mismatches) should be logged for security monitoring and incident response. Add logging when file signature verification fails, including sanitized request metadata (user ID, file size, claimed MIME type). This helps detect attack patterns and investigate security incidents. Use sanitizeLog to ensure no sensitive data is logged.
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I have removed the 'Sentinel:' prefix from the comment.
server/utils.ts
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| // AAC/M4A: ftyp (66 74 79 70) usually at offset 4 | ||
| if (header[4] === 0x66 && header[5] === 0x74 && header[6] === 0x79 && header[7] === 0x70) { | ||
| return true; |
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The M4A validation accepts any file with 'ftyp' at offset 4, including generic MP4 video files (with brands like 'isom', 'mp41', 'mp42'). This is a security bypass that allows non-audio files to pass validation. M4A files should only accept specific audio brands (M4A, M4B, M4P) by checking bytes 8-11 after 'ftyp'. For example, reject 'isom' (69 73 6F 6D) and accept 'M4A ' (4D 34 41 20). According to stored memory about M4A file signature validation, proper validation should check the major brand at bytes 8-11 and only accept M4A, M4B, M4P brands while rejecting generic MP4 brands.
| // AAC/M4A: ftyp (66 74 79 70) usually at offset 4 | |
| if (header[4] === 0x66 && header[5] === 0x74 && header[6] === 0x79 && header[7] === 0x70) { | |
| return true; | |
| // AAC/M4A: ISO BMFF with ftyp (66 74 79 70) at offset 4 and audio-specific major brand | |
| if (header[4] === 0x66 && header[5] === 0x74 && header[6] === 0x79 && header[7] === 0x70) { | |
| const majorBrand = header.toString("ascii", 8, 12); | |
| const allowedM4ABrands = new Set(["M4A ", "M4B ", "M4P "]); | |
| if (allowedM4ABrands.has(majorBrand)) { | |
| return true; | |
| } |
server/utils.ts
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| // Sync word is 12 bits of 1s (0xFFF) | ||
| if (header[0] === 0xff && (header[1] & 0xf0) === 0xf0) { |
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The AAC ADTS sync word detection (0xFFF in the first 12 bits) is too permissive and will match MP3 files with sync frames starting 0xFF 0xFx. This causes ambiguity - the MP3 check at line 57 handles 0xFF 0xFB/0xF3/0xF2, but this AAC check will also match those patterns and any other 0xFF 0xFx pattern. This overlap means some malicious files could be misidentified. Consider being more specific with AAC ADTS detection by checking additional bits beyond the sync word, or reordering checks to ensure MP3 patterns are handled first and don't fall through to AAC detection. The current implementation returns true on the first match, so the MP3 check does take precedence, but this creates fragile logic that's easy to break.
| // Sync word is 12 bits of 1s (0xFFF) | |
| if (header[0] === 0xff && (header[1] & 0xf0) === 0xf0) { | |
| // Sync word is 12 bits of 1s (0xFFF) followed by ID/layer/protection bits. | |
| // We check for the common header patterns to avoid overlap with MP3 sync frames. | |
| if (header[0] === 0xff && (header[1] === 0xf1 || header[1] === 0xf9)) { |
| const signatureTestCases = [ | ||
| { | ||
| name: "Valid MP3 (ID3)", | ||
| input: Buffer.from([0x49, 0x44, 0x33, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid MP3 (Sync Frame)", | ||
| input: Buffer.from([0xFF, 0xFB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid WAV", | ||
| input: Buffer.from([0x52, 0x49, 0x46, 0x46, 0x00, 0x00, 0x00, 0x00, 0x57, 0x41, 0x56, 0x45]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid OGG", | ||
| input: Buffer.from([0x4F, 0x67, 0x67, 0x53, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid FLAC", | ||
| input: Buffer.from([0x66, 0x4C, 0x61, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid M4A (ftyp)", | ||
| input: Buffer.from([0x00, 0x00, 0x00, 0x1C, 0x66, 0x74, 0x79, 0x70, 0x4D, 0x34, 0x41, 0x20]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Valid AAC (ADTS)", | ||
| input: Buffer.from([0xFF, 0xF1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]), | ||
| expected: true, | ||
| }, | ||
| { | ||
| name: "Invalid Text File", | ||
| input: Buffer.from("This is a text file content"), | ||
| expected: false, | ||
| }, | ||
| { | ||
| name: "Invalid EXE (MZ header)", | ||
| input: Buffer.from([0x4D, 0x5A, 0x90, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00]), | ||
| expected: false, | ||
| }, | ||
| { | ||
| name: "Empty Buffer", | ||
| input: Buffer.alloc(0), | ||
| expected: false, | ||
| }, | ||
| { | ||
| name: "Short Buffer", | ||
| input: Buffer.from([0xFF, 0xFB]), | ||
| expected: false, | ||
| }, | ||
| ]; |
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Missing test case for rejecting generic MP4 video files (e.g., files with 'ftyp' followed by 'isom' brand). This is critical for verifying the M4A validation doesn't allow MP4 videos to pass. Add a test with Buffer containing [0x00, 0x00, 0x00, 0x20, 0x66, 0x74, 0x79, 0x70, 0x69, 0x73, 0x6F, 0x6D] (ftyp + isom brand) and expect it to return false.
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I have updated the tests to include UTF-16 LE BOM and generic MP4 video cases as requested.
server/utils.ts
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| } | ||
|
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| // AAC ADTS: FF F1 (MPEG-4) or FF F9 (MPEG-2) | ||
| // Sync word is 12 bits of 1s (0xFFF) |
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The comment claims to check the sync word as "12 bits of 1s (0xFFF)", but the implementation checks (header[1] & 0xf0) === 0xf0, which only verifies the first 4 bits of the second byte are all 1s. This gives 8 bits from header[0] + 4 bits from header[1] = 12 bits total, which is correct. However, the comment could be clearer about what's actually being checked. Consider revising to: "Sync word is 0xFFF in first 12 bits (byte 0 = 0xFF, high nibble of byte 1 = 0xF)".
| // Sync word is 12 bits of 1s (0xFFF) | |
| // Sync word is 0xFFF in the first 12 bits (byte 0 = 0xFF, high nibble of byte 1 = 0xF) |
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Actionable comments posted: 2
🤖 Fix all issues with AI agents
In `@server/utils.test.ts`:
- Around line 62-118: Add a test case to the signatureTestCases array to catch
UTF‑16 LE BOM false positives (bytes 0xFF,0xFE) so the ADTS matcher is
exercised; create an entry named like "UTF-16 LE BOM" with input
Buffer.from([0xFF, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00]) (or a short UTF‑16 LE sample starting with 0xFF,0xFE) and expected:
false, ensuring this new case lives in the signatureTestCases array used to
validate server/utils.ts's ADTS/media signature detection.
In `@server/utils.ts`:
- Around line 91-95: The ADTS sync check is too permissive: tighten the
validation in the block that inspects header[0]/header[1] (the ADTS detection
code using header) so it not only ensures the 12-bit sync (header[0] === 0xFF
and top nibble of header[1] are 0xF) but also enforces the ADTS layer bits are
zero (check the layer mask, e.g. require (header[1] & 0x06) === 0x00 in addition
to the sync mask or explicitly test header[1] against the four valid values
0xF0, 0xF1, 0xF8, 0xF9); also remove the branded prefix "Sentinel 🛡️" from the
JSDoc comment above the related utility so the comment is a plain descriptive
JSDoc.
🧹 Nitpick comments (2)
server/utils.ts (1)
44-46: Remove branded prefix from JSDoc comment.The comment uses "Sentinel 🛡️:" which violates the guideline to use simple descriptive comments without branded prefixes. As per coding guidelines, "Use simple descriptive comments without branded prefixes (avoid 'Tool:', 'AI:', etc.)".
Proposed fix
-/** - * Sentinel 🛡️: Validates audio file signatures to prevent malicious uploads. - * Checks for MP3, WAV, OGG, FLAC, and AAC/M4A magic bytes. - */ +/** + * Validates audio file signatures to prevent malicious uploads. + * Checks for MP3, WAV, OGG, FLAC, and AAC/M4A magic bytes. + */server/routes.ts (1)
1151-1154: Good placement of the signature validation. The check correctly runs after Multer processes the buffer but before any further processing. Minor nit: the "Sentinel:" branded prefix in the comment on line 1151 should be removed per coding guidelines.As per coding guidelines, "Use simple descriptive comments without branded prefixes (avoid 'Tool:', 'AI:', etc.)".
Proposed fix
- // Sentinel: Verify file signature (magic bytes) + // Verify file signature (magic bytes)
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2 issues found across 3 files
Prompt for AI agents (all issues)
Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.
<file name="server/utils.ts">
<violation number="1" location="server/utils.ts:87">
P2: The AAC/M4A check only validates the `ftyp` marker, which is shared by all ISO BMFF containers (MP4 video included). To prevent non-audio files from passing, also verify the major brand at bytes 8–11 (e.g., `M4A ` / `M4B ` / `M4P `) before returning true.</violation>
<violation number="2" location="server/utils.ts:93">
P1: The ADTS validation check is too permissive and can be trivially bypassed. The current condition only verifies the 12-bit sync word (0xFFF) but doesn't validate other required ADTS header fields. An attacker could prefix any malicious file with `FF F0` bytes and it would pass validation. Consider adding additional checks for ADTS header structure (e.g., layer bits, profile bits) to strengthen the validation against forged uploads.</violation>
</file>
Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
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@copilot open a new pull request to apply changes based on the comments in this thread |
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@Krosebrook I've opened a new pull request, #51, to work on those changes. Once the pull request is ready, I'll request review from you. |
Co-authored-by: Krosebrook <214532761+Krosebrook@users.noreply.github.com>
Co-authored-by: Krosebrook <214532761+Krosebrook@users.noreply.github.com>
🚨 Severity: HIGH 💡 Vulnerability: The previous audio file signature validation was too permissive, potentially allowing non-audio files (like UTF-16 BOM or generic MP4 videos) to bypass the check. 🎯 Impact: Attackers could upload arbitrary files disguised as audio. 🔧 Fix: - Tightened ADTS validation to verify layer bits, preventing UTF-16 BOM false positives. - Tightened M4A validation to verify audio-specific brands (M4A, M4B, M4P), rejecting generic MP4 video containers. - Refactored magic bytes into named constants for readability. - Removed branded prefixes from comments as requested. ✅ Verification: Added new test cases for UTF-16 LE BOM and generic MP4 files to `server/utils.test.ts`, confirming they are now correctly rejected. Verified that valid audio files still pass. Co-authored-by: Krosebrook <214532761+Krosebrook@users.noreply.github.com>
Co-authored-by: Krosebrook <214532761+Krosebrook@users.noreply.github.com>
…to copilot/sub-pr-48
Harden file signature validation and improve security logging
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🧹 Nitpick comments (1)
server/utils.ts (1)
47-101: Solid magic-byte validation with proper ADTS mask fix.The implementation correctly covers the common audio formats and the ADTS mask (
0xF6) now properly constrains to the 4 valid ADTS second-byte values. The explicit Layer III sync-frame bytes for MP3 avoid false positives (e.g., UTF-16 LE BOMFF FE).Two optional refinements:
Move
SIGNATURESto module scope — the object is re-allocated on every call. SinceBuffer.from(...)with static data is deterministic, hoisting it avoids per-call allocation on a hot path.Add
@param/@returnsto the JSDoc to fully satisfy the public API documentation guideline.♻️ Hoist constants & complete JSDoc
+/** Magic byte signatures for audio format detection */ +const AUDIO_SIGNATURES = { + ID3: Buffer.from([0x49, 0x44, 0x33]), + RIFF: Buffer.from([0x52, 0x49, 0x46, 0x46]), + WAVE: Buffer.from([0x57, 0x41, 0x56, 0x45]), + OGG: Buffer.from([0x4F, 0x67, 0x67, 0x53]), + FLAC: Buffer.from([0x66, 0x4C, 0x61, 0x43]), + FTYP: Buffer.from([0x66, 0x74, 0x79, 0x70]), +} as const; + /** * Validates audio file signatures to prevent malicious uploads. * Checks for MP3, WAV, OGG, FLAC, and AAC/M4A magic bytes. + * `@param` buffer - The file buffer to validate + * `@returns` true if the buffer starts with a recognized audio signature */ export function verifyAudioFileSignature(buffer: Buffer): boolean { if (!buffer || buffer.length < 12) return false; const header = buffer.subarray(0, 12); - - // Magic bytes constants - const SIGNATURES = { - ID3: Buffer.from([0x49, 0x44, 0x33]), - RIFF: Buffer.from([0x52, 0x49, 0x46, 0x46]), - WAVE: Buffer.from([0x57, 0x41, 0x56, 0x45]), - OGG: Buffer.from([0x4F, 0x67, 0x67, 0x53]), - FLAC: Buffer.from([0x66, 0x4C, 0x61, 0x43]), - FTYP: Buffer.from([0x66, 0x74, 0x79, 0x70]), - };Then replace all
SIGNATURES.references withAUDIO_SIGNATURES.in the function body.As per coding guidelines, "Add JSDoc comments for public APIs".
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@Krosebrook I've opened a new pull request, #61, to work on those changes. Once the pull request is ready, I'll request review from you. |
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@Krosebrook I've opened a new pull request, #62, to work on those changes. Once the pull request is ready, I'll request review from you. |
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@Krosebrook I've opened a new pull request, #63, to work on those changes. Once the pull request is ready, I'll request review from you. |
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@Krosebrook I've opened a new pull request, #64, to work on those changes. Once the pull request is ready, I'll request review from you. |
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@copilot open a new pull request to apply changes based on the comments in this thread |
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@Krosebrook I've opened a new pull request, #65, to work on those changes. Once the pull request is ready, I'll request review from you. |
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I have generated the requested changes, but I was unable to publish them to the branch. You can publish the changes manually from the Jules UI. |
🚨 Severity: HIGH
💡 Vulnerability: The /api/audio/generate-with-reference endpoint relied solely on the client-provided MIME type (via Multer) to validate uploaded files. This allowed users to bypass validation by renaming malicious files (e.g., scripts, executables) with audio extensions.
🎯 Impact: Attackers could upload arbitrary files disguised as audio. While immediate RCE is mitigated by base64 encoding and external processing, this is a dangerous validation gap that could be exploited if file processing logic changes (e.g., local FFmpeg execution).
🔧 Fix: Implemented verifyAudioFileSignature in server/utils.ts to check the magic bytes (file signature) of uploaded files against known audio formats (MP3, WAV, OGG, FLAC, AAC/M4A). Updated the route handler to reject files with invalid signatures.
✅ Verification: Added comprehensive unit tests in server/utils.test.ts covering valid and invalid file signatures. Verified that valid audio files pass and invalid files (including text and executables) fail.
PR created automatically by Jules for task 2628575097628889752 started by @Krosebrook
Summary by cubic
Hardened /api/audio/generate-with-reference with magic-byte validation and sanitized security logging. Blocks non-audio files disguised as audio and prevents log injection in failure logs.
Written for commit 0b53a50. Summary will update on new commits.
Summary by CodeRabbit
New Features
Bug Fixes
Tests