CVE-2025-64508
📋 TL;DR
Bugsink versions before 2.0.5 are vulnerable to denial-of-service attacks via brotli compression bombs. Attackers can send specially crafted highly compressed data streams that cause memory exhaustion when decompressed, crashing the server. This affects any Bugsink instance with a publicly known DSN, which is common in JavaScript and mobile app deployments.
💻 Affected Systems
- Bugsink
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage due to memory exhaustion, potentially affecting all connected applications that rely on Bugsink for error tracking.
Likely Case
Intermittent service disruptions and degraded performance as memory resources are consumed by repeated attacks.
If Mitigated
Minimal impact with proper rate limiting, memory monitoring, and network filtering in place.
🎯 Exploit Status
Attack requires knowledge of the DSN but no authentication. Similar brotli bomb techniques are well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.5
Vendor Advisory: https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
Restart Required: Yes
Instructions:
1. Backup current Bugsink installation and data. 2. Update to Bugsink version 2.0.5 or later. 3. Restart the Bugsink service. 4. Verify the update was successful.
🔧 Temporary Workarounds
Rate Limit Incoming Requests
allImplement rate limiting on the Bugsink endpoint to prevent repeated exploitation attempts.
# Example using nginx rate limiting
limit_req_zone $binary_remote_addr zone=brotli:10m rate=10r/s;
limit_req zone=brotli burst=20 nodelay;
Restrict DSN Exposure
allLimit exposure of the DSN by using environment variables or server-side configurations instead of client-side exposure.
🧯 If You Can't Patch
- Implement network-level filtering to block suspicious brotli-compressed payloads
- Monitor memory usage and set up alerts for abnormal consumption patterns
🔍 How to Verify
Check if Vulnerable:
Check Bugsink version. If version is less than 2.0.5, system is vulnerable.Check Version:
bugsink --version or check package.json/version fileVerify Fix Applied:
Confirm Bugsink version is 2.0.5 or higher and test with normal error submission to ensure functionality.📡 Detection & Monitoring
Log Indicators:
- Unusually large memory consumption spikes
- Process crashes or restarts
- High volume of brotli-compressed requests
Network Indicators:
- Large brotli-compressed payloads to Bugsink endpoints
- Repeated requests with compressed data
SIEM Query:
source="bugsink" AND (memory_usage>90% OR process="crashed")🔗 References
- https://github.com/bugsink/bugsink/commit/3f65544aab3ad5303d97009136640de97b0676a5
- https://github.com/bugsink/bugsink/pull/266
- https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
- https://github.com/google/brotli/commit/67d78bc41db1a0d03f2e763497748f2f69946627
- https://github.com/google/brotli/issues/1327
- https://github.com/google/brotli/issues/1375
- https://github.com/google/brotli/pull/1234
- https://github.com/google/brotli/releases/tag/v1.2.0
