Http4s: Ember chunk parser lenience (TE.TE request smuggling)
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- Fix
- Fixed in 0.23.35, 1.0.0-M47
- 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
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s chunk decoder trims the chunk-size token and accepts leading plus or minus signs instead of requiring one or more hexadecimal digits followed by the required CRLF. When an intermediary forwards chunked data without re-encoding and interprets malformed chunk boundaries differently, an unauthenticated attacker can create TE.TE request smuggling that bypasses intermediary controls, poisons caches, or hijacks the request queue. The same response-path leniency can enable response smuggling against an ember-client used as a gateway when the upstream is malicious or compromised. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- http4s http4s
fixed in 0.23.35; From 1.0.0-M1 · fixed in 1.0.0-M47
- org.http4s:http4s-ember-core_2.12Maven
fixed in 0.23.35
- org.http4s:http4s-ember-core_2.13Maven
fixed in 0.23.35
- org.http4s:http4s-ember-core_3Maven
fixed in 0.23.35
- org.http4s:http4s-ember-core_2.13Maven
From 1.0.0-M1 · fixed in 1.0.0-M47
- org.http4s:http4s-ember-core_3Maven
From 1.0.0-M1 · fixed in 1.0.0-M47