CVE-2008-1501
Description
The send_user_mode function in s_user.c in (1) Undernet ircu 2.10.12.12 and earlier, (2) snircd 1.3.4 and earlier, and unspecified other ircu derivatives allows remote attackers to cause a denial of service (daemon crash) via a malformed MODE command.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Exploits
Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.
Exploit-DB
Snircd 1.3.4 - 'send_user_mode' Denial of Service
Affected software
-----------------
ircu (upto and including 2.10.12.12)
snircd (upto and including 1.3.4)
and many other ircu derivatives
Vulnerability details
---------------------
send_user_mode in s_user.c does not check that the argument after a +r mode
is present, if it is not than the NULL sentinel may be missed, causing the
function to iterate over the boundary of the array.
One possible exploit:
/mode nickname i i i i i i i i i i i i i i i r r r r s
This won't work if there's another NULL directly after the first from the
previous parsed command, if this is the case one can just append more modes
or send some other junk to the ircd.
Resolution
----------
Upgrade to the very latest version of ircu/snircd.
Disclosure timeline
-------------------
2008-03-15: Vulnerability discovered by QuakeNet and reported to Undernet.
2008-03-15: Patches released.
2008-03-17: Patches applied to public servers.
2008-03-24: Public disclosure.
--
Chris Porter (slug on QuakeNet)
http://www.warp13.co.uk
# milw0rm.com [2008-03-24]OS impact
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 0 |
| sid | Fixed | 0 |
| forky | Fixed | 0 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 0 |
References
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.