CVE-2016-8622 Information

Description

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.

CVSS Vector

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

Reference

http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html http://www.securityfocus.com/bid/94105 http://www.securitytracker.com/id/1037192 https://access.redhat.com/errata/RHSA-2018:2486 https://access.redhat.com/errata/RHSA-2018:3558 https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8622 https://curl.haxx.se/docs/adv_20161102H.html https://curl.haxx.se/docs/adv_20161102H.html https://security.gentoo.org/glsa/201701-47 https://www.tenable.com/security/tns-2016-21 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. cpe:2.3:a:haxx:libcurl::::::::

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8