A PCRE security update has been released for Ubuntu Linux 16.04 ESM.

USN-5665-1: PCRE vulnerabilities

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Ubuntu Security Notice USN-5665-1
October 10, 2022

pcre3 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM

Summary:

PCRE could be made to crash if it received specially crafted
input.

Software Description:
- pcre3: Perl 5 Compatible Regular Expression Library

Details:

It was discovered that PCRE incorrectly handled certain regular expressions.
A remote attacker could use this issue to cause applications using PCRE to
crash, resulting in a denial of service. (CVE-2017-6004)

It was discovered that PCRE incorrectly handled certain Unicode encoding. A
remote attacker could use this issue to cause applications using PCRE to
crash, resulting in a denial of service. (CVE-2017-7186)

Update instructions:

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

Ubuntu 16.04 ESM:
libpcre3 2:8.38-3.1ubuntu0.1~esm2

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

References:
  https://ubuntu.com/security/notices/USN-5665-1
CVE-2017-6004, CVE-2017-7186