Description
Off-by-one buffer overflow in the ssl_compat_directive function, as called by the rewrite_command hook for mod_ssl Apache module 2.8.9 and earlier, allows local users to execute arbitrary code as the Apache server user via .htaccess files with long entries.
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 3.0 | libapache-mod-ssl | 2.8.9-2 | DSA-135 |
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
- Apache mod_ssl 2.8.x - Off-by-One HTAccess Buffer Overflow EDB-21575 · dos · Jun 22, 2002 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-135 libapache-mod-ssl -- buffer overflow / DoS Debian Security (DSA / DLA) · Mar 9, 2026
References
- RHSA-2002:164 vendor-advisory
- apache-modssl-htaccess-bo(9415) vdb-entry
- RHSA-2003:106 vendor-advisory
- CLA-2002:504 vendor-advisory
- MDKSA-2002:048 vendor-advisory
- SuSE-SA:2002:028 vendor-advisory
- RHSA-2002:134 vendor-advisory
- RHSA-2002:136 vendor-advisory
- 20020622 Another flaw in Apache? mailing-list
- 20020628 TSL-2002-0058 - apache/mod_ssl mailing-list
- 5084 vdb-entry
- 20020624 Apache mod_ssl off-by-one vulnerability mailing-list
- RHSA-2002:135 vendor-advisory
- RHSA-2002:146 vendor-advisory
- HPSBTL0207-052 vendor-advisory
- DSA-135 vendor-advisory
- ESA-20020702-017 vendor-advisory