CVE-2021-31671
HIGHCVE-2021-31671 is a high-severity (CVSS 7.5) CWE-319 vulnerability in pgsync. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2021-31671 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Pgsync Contains Cleartext Transmission of Sensitive Information
Real-World Exposure
pgsyncReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
pgsync before 0.6.7 is affected by Information Disclosure of sensitive information. Syncing the schema with the --schema-first and --schema-only options is mishandled. For example, the sslmode connection parameter may be lost, which means that SSL would not be used.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | pgsync | all versions | 0.6.7 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pgsync. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pgsync to 0.6.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-31671 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-31671 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-31671. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-31671 in your dependencies?
O3 detects CVE-2021-31671 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.