Description
modules/m_capab.c in (1) ircd-ratbox before 3.0.8 and (2) Charybdis before 3.4.2 does not properly support capability negotiation during server handshakes, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a malformed request.
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 6.0 | ircd-ratbox | 3.0.6.dfsg-2squeeze1 | DSA-2612-1 |
Advisories 1
- DSA-2612-1 ircd-ratbox - programming error Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://rabbit.dereferenced.org/~nenolod/ASA-2012-12-31.txt
- https://github.com/atheme/charybdis/commit/ac0707aa61d9c20e9b09062294701567c9f41595.patch
- http://www.stack.nl/~jilles/irc/charybdis-3.4.2.tbz2
- [oss-security] 20130101 Re: Charybdis: Improper assumptions in the server handshake code may lead to a remote crash mailing-list
- DSA-2612 vendor-advisory
- http://www.ratbox.org/download/ircd-ratbox-3.0.8.tar.bz2