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Project	Deployment	Actions	Updated (UTC)
docs	Skipped		Jun 20, 2026 8:59pm

PR Summary

High Risk
Security fix on a shared API decompression path; incorrect streaming/cap logic could break legitimate extracts or leave residual DoS risk on hosted workers.

Overview
Hardens zip decompression in POST /api/tools/file/manage (operation: "decompress") against zip-bomb / forged-metadata attacks that could fully inflate huge entries before size limits applied.

Instead of entry.async('nodebuffer'), each safe archive entry is inflated via inflateEntryWithinCaps, which reads entry.nodeStream() and destroys the stream as soon as per-entry (MAX_DECOMPRESS_ENTRY_BYTES) or remaining total (MAX_DECOMPRESS_TOTAL_BYTES) budgets would be exceeded. Limits are enforced on actual inflated bytes, not ZIP header uncompressedSize (documented as attacker-controlled and only used for an optional fast-reject).

Successful entries still accumulate into pending before any workspace writes, preserving the prior “no partial extraction on cap breach” behavior for valid archives.

^{Reviewed by Cursor Bugbot for commit 789e99c. Configure here.}

Greptile Summary

This PR fixes a zip bomb / DoS vulnerability in the decompress route where ZIP entries with forged (or absent) declared uncompressed sizes could bypass the pre-inflation cap check and fully materialise into memory, crashing the shared Node.js worker. The fix introduces inflateEntryWithinCaps, a streaming counting sink that enforces per-entry and total size caps on the actual inflated bytes as they arrive, keeping the old declared-size check only as a cheap fast-reject for well-formed archives.

• inflateEntryWithinCaps: streams each entry via entry.nodeStream(), tears down the stream the instant cumulative output exceeds either MAX_DECOMPRESS_ENTRY_BYTES or the remaining total budget, and returns a discriminated InflateResult — peak memory is bounded to the cap plus one DEFLATE chunk.
• Route handler loop: switches from entry.async('nodebuffer') (fully materialises in memory before checking) to await inflateEntryWithinCaps(entry, MAX_DECOMPRESS_TOTAL_BYTES - totalBytes), checking the result discriminant before accumulating totalBytes.
• Error handler: per the prior review, correctly calls stream.destroy() before rejecting so the JSZip readable isn't left dangling on a mid-inflation DEFLATE error.

Confidence Score: 5/5

The change is a tightly scoped security fix confined to one helper function and its call site; the streaming teardown logic is sound, the idempotent settle() guard prevents double-resolve on any exit path, and the error handler now correctly destroys the stream before rejecting.

The new inflateEntryWithinCaps function correctly enforces caps on real inflated bytes. settle() is idempotent and calls stream.destroy() before resolving, preventing resource leaks. The error handler guards with if (settled) return and also calls stream.destroy() — matching the teardown that every other exit path performs. The route handler's totalBytes bookkeeping remains consistent: remainingTotalBudget is always non-negative when passed in, and totalBytes can never exceed MAX_DECOMPRESS_TOTAL_BYTES after a successful inflate. The advisory fast-reject on declared sizes is preserved and correctly labelled as non-authoritative.

No files require special attention; the single changed file is apps/sim/app/api/tools/file/manage/route.ts and the security-critical streaming logic has been reviewed and found correct.

Important Files Changed

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant R as Route Handler
    participant I as inflateEntryWithinCaps
    participant S as JSZip nodeStream
    participant Z as DEFLATE decompressor

    R->>I: call(entry, remainingTotalBudget)
    I->>S: entry.nodeStream()
    I->>S: listen on data/end/error
    S->>Z: pipe decompressed data
    loop Each chunk
        Z-->>S: deflated chunk
        S-->>I: emit data chunk
        alt "size > MAX_DECOMPRESS_ENTRY_BYTES"
            I->>S: stream.destroy()
            I-->>R: ok false, reason entry
        else "size > remainingTotalBudget"
            I->>S: stream.destroy()
            I-->>R: ok false, reason total
        else within caps
            I->>I: chunks.push(chunk)
        end
    end
    S-->>I: emit end
    I-->>R: ok true, buffer Buffer.concat(chunks)
    Note over R: totalBytes += result.buffer.length
    Note over R: pending.push segments and buffer

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sequenceDiagram
    participant R as Route Handler
    participant I as inflateEntryWithinCaps
    participant S as JSZip nodeStream
    participant Z as DEFLATE decompressor

    R->>I: call(entry, remainingTotalBudget)
    I->>S: entry.nodeStream()
    I->>S: listen on data/end/error
    S->>Z: pipe decompressed data
    loop Each chunk
        Z-->>S: deflated chunk
        S-->>I: emit data chunk
        alt "size > MAX_DECOMPRESS_ENTRY_BYTES"
            I->>S: stream.destroy()
            I-->>R: ok false, reason entry
        else "size > remainingTotalBudget"
            I->>S: stream.destroy()
            I-->>R: ok false, reason total
        else within caps
            I->>I: chunks.push(chunk)
        end
    end
    S-->>I: emit end
    I-->>R: ok true, buffer Buffer.concat(chunks)
    Note over R: totalBytes += result.buffer.length
    Note over R: pending.push segments and buffer

_{Reviews (2): Last reviewed commit: "fix(file-decompress): destroy inflate st..." | Re-trigger Greptile}

@greptile

@cursor review