CVE-2016-1962

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Last Modified: UTC

Description

The CVE Program describes this issue as:

Use-after-free vulnerability in the mozilla::DataChannelConnection::Close function in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7 allows remote attackers to execute arbitrary code by leveraging mishandling of WebRTC data-channel connections.

Additional information

  • Bugzilla 1315578: Mozilla: Use-after-free when using multiple WebRTC data channels (MFSA 2016-25)
  • CWE-416: Use After Free
  • FAQ: Frequently asked questions about CVE-2016-1962

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v2 Score Breakdown
Red HatNVD

CVSS v2 Base Score

6.8

10

Attack Vector

Network

Network

Access Complexity

Medium

Low

Authentication

None

None

Confidentiality Impact

Partial

Complete

Integrity Impact

Partial

Complete

Availability Impact

Partial

Complete

CVSS v2 Vector

Red Hat: AV:N/AC:M/Au:N/C:P/I:P/A:P

NVD: AV:N/AC:L/Au:N/C:C/I:C/A:C

Understanding the Weakness (CWE)

CWE-416

Integrity

Technical Impact: Modify Memory

The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.

Availability

Technical Impact: DoS: Crash, Exit, or Restart

If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands

If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Acknowledgements

Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Dominique Hazaël-Massieux as the original reporter.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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