Undertow: undertow: chunkreader message length permits chunk-size overflow
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Undertow web server, a Java-based HTTP server, is affected through its handling of chunked transfer encoding in incoming requests. A crafted chunk size can bypass the server's length check, causing the server to cut off a request body early and treat the leftover data as a separate request, which enables HTTP request smuggling.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
A flaw was found in the ChunkReader component of the Undertow web server, which is used to handle chunked transfer encoding in HTTP requests. The issue occurs because a security check for the chunk size is performed before the value is shifted, allowing a specifically crafted 15-digit chunk size to bypass the limit and overflow into internal state flags. This can cause the server to terminate a request body prematurely and interpret the remaining data as a separate, smuggled request.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- undertow-servlet
Version range not reported
- pki-core:10.6/resteasy
Version range not reported
- pki-deps:10.6/resteasy
Version range not reported
- resteasy
Version range not reported
- undertow-servlet
Version range not reported
- jboss-eap-7/eap74-els-openjdk11-openshift-rhel8
Version range not reported
- jboss-eap-7/eap74-els-openjdk17-openshift-rhel8
Version range not reported
- jboss-eap-7/eap74-els-openjdk8-openshift-rhel8
Version range not reported
- undertow-servlet
Version range not reported
- undertow-servlet
Version range not reported
- undertow-servlet
Version range not reported
- undertow-servlet
Version range not reported