CVE-2018-15857 Use after free in n/a

What is CVE-2018-15857?

CVE-2018-15857 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 25 Aug 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local attackers to crash xkbcommon keymap parsers or possibly have unspecified other impact by supplying a crafted keymap file.

Weakness: CWE-416

Which versions are affected by CVE-2018-15857?

It affects 3 products.

Products include Canonical Ubuntu Linux, Xkbcommon Libxkbcommon, Xkbcommon Xkbcommon.

How do I fix CVE-2018-15857?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2018-15857 being exploited?

There is no known exploitation of CVE-2018-15857 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-15857, GHSA-8vxx-7whg-r47h, UBUNTU-CVE-2018-15857.