SB2018073120 - Out-of-bounds write in curl.haxx.se libcurl



SB2018073120 - Out-of-bounds write in curl.haxx.se libcurl

Published: July 31, 2018 Updated: August 3, 2020

Security Bulletin ID SB2018073120
Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2016-8622)

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.


Remediation

Install update from vendor's website.