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CVE-2023-34981

HIGH

Apache Tomcat vulnerable to information leak

Also known asBIT-tomcat-2023-34981GHSA-mppv-79ch-vw6q
Published
Jun 21, 2023
Updated
Apr 10, 2026
Affected
4 pkgs
Patched
4 / 4
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
1.1%probability of exploitation in next 30 days
Lower Risk62th percentile+0.84%
0.00%0.54%1.08%1.62%0.3%1.1%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

4 pkgs affected
☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat:tomcat-coyote

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A regression in the fix for bug 66512 in Apache Tomcat 11.0.0-M5, 10.1.8, 9.0.74 and 8.5.88 meant that, if a response did not include any HTTP headers no AJP SEND_HEADERS messare woudl be sent for the response which in turn meant that at least one AJP proxy (mod_proxy_ajp) would use the response headers from the previous request leading to an information leak.

Affected Packages

4 total 4 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.apache.tomcat.embed:tomcat-embed-core≥ 11.0.0-M5&&< 11.0.0-M611.0.0-M6
☕Mavenorg.apache.tomcat.embed:tomcat-embed-core≥ 10.1.8&&< 10.1.910.1.9
☕Mavenorg.apache.tomcat.embed:tomcat-embed-core≥ 9.0.74&&< 9.0.759.0.75
☕Mavenorg.apache.tomcat:tomcat-coyote≥ 8.5.88&&< 8.5.898.5.89

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat.embed:tomcat-embed-core. 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.

  2. Fix

    Update org.apache.tomcat.embed:tomcat-embed-core to 11.0.0-M6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34981 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether CVE-2023-34981 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-2023-34981. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A regression in the fix for bug 66512 in Apache Tomcat 11.0.0-M5, 10.1.8, 9.0.74 and 8.5.88 meant that, if a response did not include any HTTP headers no AJP SEND_HEADERS messare woudl be sent for the response which in turn meant that at least one AJP proxy (mod_proxy_ajp) would use the response headers from the previous request leading to an information leak.
O3 Security · Impact-Aware SCA

Is CVE-2023-34981 in your dependencies?

O3 detects CVE-2023-34981 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works