Description
ssl3_get_record in s3_pkt.c for OpenSSL before 0.9.7a and 0.9.6 before 0.9.6i does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the "Vaudenay timing attack."
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 ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openssl | 0.9.7a-1 | — |
| Debian 13 | openssl | 0.9.7a-1 | — |
| Debian 12 | openssl | 0.9.7a-1 | — |
| Debian 3.0 | openssl | 0.9.6c-2.woody.2 | DSA-253 |
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.
Exploit-DB 1
- OpenSSL 0.9.x - CBC Error Information Leakage EDB-22264 · remote · Feb 19, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-253 openssl - information leak Debian Security (DSA / DLA) · Mar 9, 2026
References
- 3945 vdb-entry
- ssl-cbc-information-leak(11369) vdb-entry
- http://www.openssl.org/news/secadv_20030219.txt
- 2003-0005 vendor-advisory
- DSA-253 vendor-advisory
- RHSA-2003:205 vendor-advisory
- ESA-20030220-005 vendor-advisory
- N-051 third-party-advisory government-resource
- 20030219 OpenSSL 0.9.7a and 0.9.6i released mailing-list
- RHSA-2003:104 vendor-advisory
- 6884 vdb-entry
- MDKSA-2003:020 vendor-advisory
- CLSA-2003:570 vendor-advisory
- 20030219 [OpenPKG-SA-2003.013] OpenPKG Security Advisory (openssl) mailing-list
- GLSA-200302-10 vendor-advisory
- RHSA-2003:082 vendor-advisory
- RHSA-2003:063 vendor-advisory
- RHSA-2003:062 vendor-advisory