Description
LibreSSL ocspcheck through 4.4.0 contains a CRLF injection vulnerability that allows attackers to inject HTTP headers by embedding CR/LF sequences in a certificate's AIA OCSP URI path. Because url2host() copies the path without rejecting control characters and http_open() places it in the POST request line, attackers can inject headers or split OCSP requests sent to the responder host.
Metrics
CVSS 3.1 3.7/10
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| OpenBSD | LibreSSL | <= 4.4.0 |
References
- https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt
- https://github.com/libressl/portable
- https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c#L344
- https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/ocspcheck.c#L154
- https://github.com/openbsd/src/commit/3adb7688a5bcfb675fa6d8b10e242022d620a23d
- https://github.com/openbsd/src/commit/6efdc4cce3fac9fa7208a9452f84de34c5a68e9f
- https://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-crlf-injection-via-aia-ocsp-url-path
Timeline
- Published
- Oct 28, 2026
- Last modified
- Oct 28, 2026
- NVD status
- Deferred