CVE-2022-42252 — tomcat-embed-core
HIGHCVE-2022-42252 is a high-severity (CVSS 7.5) CWE-444 vulnerability in org.apache.tomcat.embed:tomcat-embed-core. A fix is available for org.apache.tomcat.embed:tomcat-embed-core — see the affected versions and patch details below.
Apache Tomcat request smuggling via malformed content-length
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-42252.
EPSS Exploitation Probability
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.
How urgent is this, really
CVE-2022-42252 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.apache.tomcat.embed:tomcat-embed-core☕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☕org.apache.tomcat:tomcat-coyote☕org.apache.tomcat:tomcat-coyoteReal-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
If Apache Tomcat 8.5.0 to 8.5.82, 9.0.0-M1 to 9.0.67, 10.0.0-M1 to 10.0.26 or 10.1.0-M1 to 10.1.0 was configured to ignore invalid HTTP headers via setting rejectIllegalHeader to false (the default for 8.5.x only), Tomcat did not reject a request containing an invalid Content-Length header making a request smuggling attack possible if Tomcat was located behind a reverse proxy that also failed to reject the request with the invalid header.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 8.5.0&&< 8.5.83 | 8.5.83org.apache.tomcat.embed:tomcat-embed-core:8.5.83 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 9.0.0-M1&&< 9.0.68 | 9.0.68org.apache.tomcat.embed:tomcat-embed-core:9.0.68 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 10.0.0-M1&&< 10.0.27 | 10.0.27org.apache.tomcat.embed:tomcat-embed-core:10.0.27 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 10.1.0-M1&&< 10.1.1 | 10.1.1org.apache.tomcat.embed:tomcat-embed-core:10.1.1 |
| ☕Maven | org.apache.tomcat:tomcat-coyote | ≥ 9.0.0-M1&&< 9.0.68 | 9.0.68org.apache.tomcat:tomcat-coyote:9.0.68 |
| ☕Maven | org.apache.tomcat:tomcat-coyote | ≥ 10.0.0-M1&&< 10.0.27 | 10.0.27org.apache.tomcat:tomcat-coyote:10.0.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat.embed:tomcat-embed-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat.embed:tomcat-embed-core to 8.5.83 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-42252 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-42252 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-42252. 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.
Red Hat Satellite does not include the affected Apache Tomcat, however, Tomcat is shipped with Red Hat Enterprise Linux and consumed by the Candlepin component of Satellite. Red Hat Satellite users are therefore advised to check the impact state of Red Hat Enterprise Linux, since any necessary fixes will be…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat JBoss Web Server 5 | jws5-tomcat | RHSA-2023:1664 |
| Red Hat JBoss Web Server 5.7 on RHEL 7 | jws5-tomcat-0:9.0.62-13.redhat_00011.1.el7jws | RHSA-2023:1663 |
Frequently Asked Questions
Is CVE-2022-42252 in your dependencies?
O3 Security finds CVE-2022-42252 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.