LibreSSL ocspcheck through 4.4.0 CRLF Injection via AIA OCSP URL Path
Impact
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.
Source excerpt · VulnCheckAffected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
OpenBSD · LibreSSL
Other versions: unaffected
| Version / range | Source status |
|---|---|
| 0 through 4.4.0 (inclusive) | affected |
Original source 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.
References
- Patch github.com/openbsd/src/commit/6efdc4cce3fac9fa7208a9452f84de34c5a68e9f
- Patch github.com/openbsd/src/commit/3adb7688a5bcfb675fa6d8b10e242022d620a23d
- Source reference github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c
- Source reference github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/ocspcheck.c
- Source reference ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt
- Source reference github.com/libressl/portable
- Security advisory www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-crlf-injection-via-aia-ocsp-url-path