# CVE-2009-1959: Memory corruption in n/a

> Remote IRC servers can crash the irssi client via an off-by-one error in event handling, causing a denial of service.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Jun 2009
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-1959, GHSA-2v73-9rwq-75qc

## What is CVE-2009-1959?

CVE-2009-1959 is a medium-severity memory corruption vulnerability in n/a, published on 6 Jun 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-189

## Which versions are affected by CVE-2009-1959?

It affects 1 product.


Products: Irssi Irssi.

## How do I fix CVE-2009-1959?

Upgrade to a fixed version.

## Is CVE-2009-1959 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-1959 exists.

Public exploit code:

- Irssi 0.8.13 - 'WALLOPS' Message Off-by-One Heap Memory Corruption (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2002-1840](https://insights.sbomify.com/CVE-2002-1840/): Hardcoded credentials in n/a (critical 10.0)
- [CVE-2017-10965](https://insights.sbomify.com/CVE-2017-10965/): Null dereference in n/a (critical 9.8)
- [CVE-2017-10966](https://insights.sbomify.com/CVE-2017-10966/): Use after free in n/a (critical 9.8)
- [CVE-2017-7191](https://insights.sbomify.com/CVE-2017-7191/): Use after free in n/a (critical 9.8)
- [CVE-2007-4396](https://insights.sbomify.com/CVE-2007-4396/): Command injection in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-1959 and fix it if it is affected.

What it is: CVE-2009-1959 is a medium-severity memory corruption vulnerability in n/a, published on 6 Jun 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-1959 exists.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2009-1959/ (Markdown: https://insights.sbomify.com/CVE-2009-1959/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-1959
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-1959
- OSV: https://osv.dev/vulnerability/CVE-2009-1959

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-1959/
Summaries are generated and may contain mistakes; the official description above is the record.