Description
Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- OpenSSL ASN.1 < 0.9.6j/0.9.7b - Brute Forcer for Parsing Bugs EDB-146 · dos · Oct 9, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- DSA-393 openssl - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-394 openssl095 - ASN.1 parsing vulnerability Debian Security (DSA / DLA) · Mar 9, 2026
References
- oval:org.mitre.oval:def:5292 vdb-entry signature
- RHSA-2003:292 vendor-advisory
- VU#255484 third-party-advisory
- ADV-2006-3900 vdb-entry
- DSA-393 vendor-advisory
- http://www-1.ibm.com/support/docview.wss?uid=swg21247112
- http://www.uniras.gov.uk/vuls/2003/006489/openssl.htm
- DSA-394 vendor-advisory
- RHSA-2003:291 vendor-advisory
- CA-2003-26 third-party-advisory
- 22249 third-party-advisory
- oval:org.mitre.oval:def:4254 vdb-entry signature
- 8732 vdb-entry
- 201029 vendor-advisory
- http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=104893
- ESA-20030930-027 vendor-advisory