# CVE-2011-1947: Denial of service in n/a

> Remote servers can cause fetchmail to hang by delaying responses after STARTTLS or STLS requests, leading to 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:** 2 Jun 2011
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-1947, GHSA-xrcr-j9jp-xv96

## What is CVE-2011-1947?

CVE-2011-1947 is a medium-severity denial of service vulnerability in n/a, published on 2 Jun 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

fetchmail 5.9.9 through 6.3.19 does not properly limit the wait time after issuing a (1) STARTTLS or (2) STLS request, which allows remote servers to cause a denial of service (application hang) by acknowledging the request but not sending additional packets.

Weakness: CWE-399

## Which versions are affected by CVE-2011-1947?

It affects 1 product.


Products: Fetchmail Fetchmail.

## How do I fix CVE-2011-1947?

Upgrade to a fixed version.

## Is CVE-2011-1947 being exploited?

There is no known exploitation of CVE-2011-1947 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2001-1009](https://insights.sbomify.com/CVE-2001-1009/): Integer overflow in n/a (critical 10.0)
- [CVE-2001-0101](https://insights.sbomify.com/CVE-2001-0101/): Other in n/a (critical 10.0)
- [CVE-2006-5867](https://insights.sbomify.com/CVE-2006-5867/): Weak cryptography in n/a (high 7.8)
- [CVE-2006-5974](https://insights.sbomify.com/CVE-2006-5974/): Null dereference in n/a (high 7.8)
- [CVE-2005-4348](https://insights.sbomify.com/CVE-2005-4348/): Denial of service in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-1947 and fix it if it is affected.

What it is: CVE-2011-1947 is a medium-severity denial of service vulnerability in n/a, published on 2 Jun 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2011-1947 in the wild and no public exploit code.

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-2011-1947/ (Markdown: https://insights.sbomify.com/CVE-2011-1947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-1947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-1947
- OSV: https://osv.dev/vulnerability/CVE-2011-1947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-1947/
Summaries are generated and may contain mistakes; the official description above is the record.