# CVE-2011-1527: Null dereference in n/a

> Remote attackers can crash the Kerberos KDC daemon via a crafted kinit request when the LDAP backend is enabled.

- **Severity:** High 7.8 (`AV:N/AC:L/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Oct 2011
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-1527, GHSA-848m-2rw5-f2f2

## What is CVE-2011-1527?

CVE-2011-1527 is a high-severity vulnerability in Mit Kerberos 5, published on 20 Oct 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The kdb_ldap plugin in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 through 1.9.1, when the LDAP back end is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a kinit operation with incorrect string case for the realm, related to the is_principal_in_realm, krb5_set_error_message, krb5_ldap_get_principal, and process_as_req functions.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2011-1527?

It affects 1 product.


Products: Mit Kerberos 5.

## How do I fix CVE-2011-1527?

Apply the vendor's patch.

## Is CVE-2011-1527 being exploited?

There is no known exploitation of CVE-2011-1527 in the wild and no public exploit code.

## Other vulnerabilities in Mit Kerberos 5

- [CVE-2011-0285](https://insights.sbomify.com/CVE-2011-0285/): Use after free in n/a (critical 10.0)
- [CVE-2008-0947](https://insights.sbomify.com/CVE-2008-0947/): Memory corruption in n/a (critical 10.0)
- [CVE-2007-5902](https://insights.sbomify.com/CVE-2007-5902/): Integer overflow in n/a (critical 10.0)
- [CVE-2007-4743](https://insights.sbomify.com/CVE-2007-4743/): Memory corruption in n/a (critical 10.0)
- [CVE-2007-3999](https://insights.sbomify.com/CVE-2007-3999/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-1527 and fix it if it is affected.

What it is: CVE-2011-1527 is a high-severity vulnerability in Mit Kerberos 5, published on 20 Oct 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-2011-1527 in the wild and no public exploit code.

Affected product: Mit Kerberos 5. 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-2011-1527/ (Markdown: https://insights.sbomify.com/CVE-2011-1527/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-1527
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-1527
- OSV: https://osv.dev/vulnerability/CVE-2011-1527

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-1527/
Summaries are generated and may contain mistakes; the official description above is the record.