# CVE-2011-2666: Information disclosure in n/a

> Remote attackers can enumerate valid SIP account names by observing response differences when the alwaysauthreject option is disabled in Asterisk.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:P/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Jul 2011
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-2666, GHSA-6w9r-hx89-h863

## What is CVE-2011-2666?

CVE-2011-2666 is a medium-severity vulnerability in Digium Asterisk, published on 6 Jul 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The default configuration of the SIP channel driver in Asterisk Open Source 1.4.x through 1.4.41.2 and 1.6.2.x through 1.6.2.18.2 does not enable the alwaysauthreject option, which allows remote attackers to enumerate account names by making a series of invalid SIP requests and observing the differences in the responses for different usernames, a different vulnerability than CVE-2011-2536.

Weakness: CWE-16

## Which versions are affected by CVE-2011-2666?

It affects 1 product.


Products: Digium Asterisk.

## How do I fix CVE-2011-2666?

Change a configuration setting.

## Is CVE-2011-2666 being exploited?

There is no known exploitation of CVE-2011-2666 in the wild and no public exploit code.

## Other vulnerabilities in Digium Asterisk

- [CVE-2017-14100](https://insights.sbomify.com/CVE-2017-14100/): Command injection in n/a (critical 9.8)
- [CVE-2014-8418](https://insights.sbomify.com/CVE-2014-8418/): Privilege escalation in n/a (critical 9.0)
- [CVE-2011-1599](https://insights.sbomify.com/CVE-2011-1599/): Missing authorization in n/a (critical 9.0)
- [CVE-2017-16671](https://insights.sbomify.com/CVE-2017-16671/): Memory corruption in n/a (high 8.8)
- [CVE-2017-7617](https://insights.sbomify.com/CVE-2017-7617/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-2666 and fix it if it is affected.

What it is: CVE-2011-2666 is a medium-severity vulnerability in Digium Asterisk, published on 6 Jul 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-2011-2666 in the wild and no public exploit code.

Affected product: Digium Asterisk. 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-2011-2666/ (Markdown: https://insights.sbomify.com/CVE-2011-2666/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-2666
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-2666
- OSV: https://osv.dev/vulnerability/CVE-2011-2666

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-2666/
Summaries are generated and may contain mistakes; the official description above is the record.