LibreSSL ocspcheck through 4.4.0 Memory Exhaustion via Unbounded OCSP HTTP Response
Impact
LibreSSL ocspcheck through 4.4.0 contains a memory exhaustion vulnerability that allows malicious OCSP responders to exhaust memory by sending unbounded HTTP responses. Attackers controlling the responder or intercepting plain HTTP AIA OCSP traffic can stream endless headers or body data to http_head_read() and http_body_read(), denying certificate status checks.
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 memory exhaustion vulnerability that allows malicious OCSP responders to exhaust memory by sending unbounded HTTP responses. Attackers controlling the responder or intercepting plain HTTP AIA OCSP traffic can stream endless headers or body data to http_head_read() and http_body_read(), denying certificate status checks.
References
- Patch github.com/openbsd/src/commit/bf5da63f53179ef423d18c56d6da89eaefb56228
- Patch github.com/openbsd/src/commit/de4274c56c9ace88232591d4c919d79281a8de59
- Source reference github.com/openbsd/src/blob/f6f428241d469cf434e60b73fc834d0448f068d5/usr.sbin/ocspcheck/http.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-memory-exhaustion-via-unbounded-ocsp-http-response