---
title: "CVE-2015-7540\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2015-7540?format=md
keywords: index, follow
---

# CVE-2015-7540

Publication date 16 December 2015

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2015-7540?format=md#impact-score)

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## Description

The LDAP server in the AD domain controller in Samba 4.x before 4.1.22 does
not check return values to ensure successful ASN.1 memory allocation, which
allows remote attackers to cause a denial of service (memory consumption
and daemon crash) via crafted packets.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2015-7540?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| samba | 17.04 zesty | Fixed 2:4.3.3+dfsg-1ubuntu1 |
| 16.10 yakkety | Fixed 2:4.3.3+dfsg-1ubuntu1 |
| 16.04 LTS xenial | Fixed 2:4.3.3+dfsg-1ubuntu1 |
| 15.10 wily | Fixed 2:4.1.17+dfsg-4ubuntu3.1 |
| 15.04 vivid | Fixed 2:4.1.13+dfsg-4ubuntu3.1 |
| 14.04 LTS trusty | Fixed 2:4.1.6+dfsg-1ubuntu2.14.04.11 |
| 12.04 LTS precise | Not affected |
| samba4 | 17.04 zesty | Not in release |
| 16.10 yakkety | Not in release |
| 16.04 LTS xenial | Not in release |
| 15.10 wily | Not in release |
| 15.04 vivid | Not in release |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Ignored end of life |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2015-7540?format=md#patch-details)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

says 4.0.0 to 4.1.21

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| samba | * Upstream:   <https://git.samba.org/?p=samba.git;a=commit;h=530d50a1abdcdf4d1775652d4c456c1274d83d8d> * Upstream:   <https://git.samba.org/?p=samba.git;a=commit;h=9d989c9dd7a5b92d0c5d65287935471b83b6e884> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-7540)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2015-7540)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2015-7540)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2015-7540)

### Related Ubuntu Security Notices (USN)

+ [USN-2855-1](https://usn.ubuntu.com/USN-2855-1)
+ Samba vulnerabilities
+ 5 January 2016

### Other references

* <https://www.samba.org/samba/security/CVE-2015-7540.html>
* <https://www.cve.org/CVERecord?id=CVE-2015-7540>