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

USN-5026-2: QPDF vulnerabilities

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Ubuntu Security Notice USN-5026-2
August 02, 2021

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

- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in QPDF.

Software Description:
- qpdf: tools for transforming and inspecting PDF files

Details:

USN-5026-1 fixed several vulnerabilities in QPDF. This update provides
the corresponding update for Ubuntu 16.04 ESM.
Original advisory details:

It was discovered that QPDF incorrectly handled certain malformed PDF
files. A remote attacker could use this issue to cause QPDF to consume
resources, resulting in a denial of service. (CVE-2018-18020)

It was discovered that QPDF incorrectly handled certain malformed PDF
files. A remote attacker could use this issue to cause QPDF to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2021-36978)

Update instructions:

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

Ubuntu 16.04 ESM:
libqpdf21 8.0.2-3~16.04.1+esm1
qpdf 8.0.2-3~16.04.1+esm1

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

References:
  https://ubuntu.com/security/notices/USN-5026-2
  https://ubuntu.com/security/notices/USN-5026-1
CVE-2018-18020, CVE-2021-36978