A Mercurial security update has been released for Ubuntu Linux 18.04 LTS.

USN-5102-1: Mercurial vulnerabilities

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Ubuntu Security Notice USN-5102-1
October 04, 2021

mercurial vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Mercurial.

Software Description:
- mercurial: easy-to-use, scalable distributed version control system

Details:

It was discovered that Mercurial mishandled symlinks in subrepositories. An
attacker could use this issue to write arbitrary files to the
target’s filesystem. (CVE-2019-3902)

It was discovered that Mercurial incorrectly handled certain manifest files.
An attacker could use this issue to cause a denial of service and possibly
execute arbitrary code. (CVE-2018-17983)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
mercurial 4.5.3-1ubuntu2.2
mercurial-common 4.5.3-1ubuntu2.2

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5102-1
CVE-2018-17983, CVE-2019-3902

Package Information:
  https://launchpad.net/ubuntu/+source/mercurial/4.5.3-1ubuntu2.2