---
title: "CVE-2015-6834\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-2015-6834?format=md
keywords: index, follow
---

# CVE-2015-6834

Publication date 9 September 2015

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2015-6834?format=md#impact-score)

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## Description

Multiple use-after-free vulnerabilities in PHP before 5.4.45, 5.5.x before
5.5.29, and 5.6.x before 5.6.13 allow remote attackers to execute arbitrary
code via vectors related to (1) the Serializable interface, (2) the
SplObjectStorage class, and (3) the SplDoublyLinkedList class, which are
mishandled during unserialization.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| php5 | 15.04 vivid | Fixed 5.6.4+dfsg-4ubuntu6.3 |
| 14.04 LTS trusty | Fixed 5.5.9+dfsg-1ubuntu4.13 |
| 12.04 LTS precise | Fixed 5.3.10-1ubuntu3.20 |

---

* [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-2015-6834?format=md#patch-details)

### 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 |
| --- | --- |
| php5 | * Upstream:   <http://git.php.net/?p=php-src.git;a=commit;h=e8429400d40e3c3aa4b22ba701991d698a2f3b2f> * Upstream:   <http://git.php.net/?p=php-src.git;a=commit;h=f06a069c462d37c2e009f6d1d93b8c8e7b713393> * Upstream:   <http://git.php.net/?p=php-src.git;a=commit;h=259057b2a484747a6c73ce54c4fa0f5acbd56179> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-6834)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2015-6834)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2015-6834)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2015-6834)

### Related Ubuntu Security Notices (USN)

+ [USN-2758-1](https://usn.ubuntu.com/USN-2758-1)
+ PHP vulnerabilities
+ 30 September 2015

### Other references

* <http://www.openwall.com/lists/oss-security/2015/09/07/5>
* <https://www.cve.org/CVERecord?id=CVE-2015-6834>