A libpcap security update has been released for Ubuntu Linux 19.04, 18.04 LTS, 16.04 LTS, and 14.04 ESM

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Ubuntu Security Notice USN-4221-1
December 11, 2019

libpcap vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.04
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

Summary:

Applications using libpcap could be made to crash if given specially
crafted data.

Software Description:
- libpcap: Library for for user-level network packet capture

Details:

It was discovered that libpcap did not properly validate PHB headers in
some situations. An attacker could use this to cause a denial of service
(memory exhaustion).

Update instructions:

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

Ubuntu 19.04:
libpcap0.8 1.8.1-6ubuntu1.19.04.1

Ubuntu 18.04 LTS:
libpcap0.8 1.8.1-6ubuntu1.18.04.1

Ubuntu 16.04 LTS:
libpcap0.8 1.7.4-2ubuntu0.1

Ubuntu 14.04 ESM:
libpcap0.8 1.5.3-2ubuntu0.1

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

References:
  https://usn.ubuntu.com/4221-1
CVE-2019-15165

Package Information:
  https://launchpad.net/ubuntu/+source/libpcap/1.8.1-6ubuntu1.19.04.1
  https://launchpad.net/ubuntu/+source/libpcap/1.8.1-6ubuntu1.18.04.1
  https://launchpad.net/ubuntu/+source/libpcap/1.7.4-2ubuntu0.1