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Fencer Vulns
medium 5.0

CVE-2009-1959 json

Off-by-one error in the event_wallops function in fe-common/irc/fe-events.c in irssi 0.8.13 allows remote IRC servers to cause a denial of…

published 2009-06-06 17 y ago modified 2026-06-16 4 mo ago also EUVD-2009-1954

cvss
5.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
8.4%
EPSS 8.4% chance of exploitation in 30 days, percentile 95%
public exploits
1
Exploit-DB

Summary

Off-by-one error in the event_wallops function in fe-common/irc/fe-events.c in irssi 0.8.13 allows remote IRC servers to cause a denial of service (crash) via an empty command, which triggers a one-byte buffer under-read and a one-byte buffer underflow.

Patch / fix

  • irssi Debian 14, Debian 13, Debian 12 0.8.13-2

debian advisories DEBIAN-CVE-2009-1959

  • irssi openSUSE Tumbleweed 0.8.20-3.1

opensuse advisories openSUSE-SU-2024:10455-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-1959 updated

irssi: off-by-one error in the event_wallops

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-33041)
  2. Published

Exploit prediction

8.38% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-33041 Irssi 0.8.13 - 'WALLOPS' Message Off-by-One Heap Memory Corruption dos, 2009-05-15
  • xorl.wordpress.com http://xorl.wordpress.com/2009/05/28/irssi-event_wallops-off-by-one-readwrite/ referenced PoC, tagged "exploit" by a source, unverified
  • irssi.org http://www.irssi.org/ChangeLog referenced PoC, tagged "exploit" by a source, unverified
  • bugs.irssi.org http://bugs.irssi.org/index.php?do=details&task_id=662 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.