CVE-2019-25025 is a medium-severity (CVSS 5.3) vulnerability in activerecord-session_store. O3 Security confirms whether CVE-2019-25025 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Activerecord-session_store Vulnerable to Timing Attack
Real-World Exposure
activerecord-session_storeReal-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
The activerecord-session_store (aka Active Record Session Store) component through 1.1.3 for Ruby on Rails does not use a constant-time approach when delivering information about whether a guessed session ID is valid. Consequently, remote attackers can leverage timing discrepancies to achieve a correct guess in a relatively short amount of time. This is a related issue to CVE-2019-16782.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | activerecord-session_store | all versions | 2.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activerecord-session_store. 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 activerecord-session_store to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-25025 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-2019-25025 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-2019-25025. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2019-25025 in your dependencies?
O3 detects CVE-2019-25025 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.