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Ubuntu Security Notice USN-5474-1
June 08, 2022

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

- Ubuntu 22.04 LTS
- Ubuntu 21.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Varnish Cache.

Software Description:
- varnish: state of the art, high-performance web accelerator

Details:

It was dicovered that Varnish Cache did not clear a pointer between the
handling of one client request and the next request within the same connection.
A remote attacker could possibly use this issue to obtain sensitive
information. (CVE-2019-20637)

It was discovered that Varnish Cache could have an assertion failure when a
TLS termination proxy uses PROXY version 2. A remote attacker could possibly
use this issue to restart the daemon and cause a performance loss.
(CVE-2020-11653)

It was discovered that Varnish Cache allowed request smuggling and VCL
authorization bypass via a large Content-Length header for a POST
request. A remote attacker could possibly use this issue to obtain sensitive
information. (CVE-2021-36740)

It was discovered that Varnish Cache allowed request smuggling for HTTP/1
connections. A remote attacker could possibly use this issue to obtain
sensitive information. (CVE-2022-23959)

Update instructions:

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

Ubuntu 22.04 LTS:
  libvarnishapi2                  6.6.1-1ubuntu0.2
  varnish                         6.6.1-1ubuntu0.2

Ubuntu 21.10:
  libvarnishapi2                  6.5.2-1ubuntu0.2
  varnish                         6.5.2-1ubuntu0.2

Ubuntu 20.04 LTS:
  libvarnishapi2                  6.2.1-2ubuntu0.1
  varnish                         6.2.1-2ubuntu0.1

Ubuntu 18.04 LTS:
  libvarnishapi1                  5.2.1-1ubuntu0.1
  varnish                         5.2.1-1ubuntu0.1

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

References:
  https://ubuntu.com/security/notices/USN-5474-1
  CVE-2019-20637, CVE-2020-11653, CVE-2021-36740, CVE-2022-23959

Package Information:
  https://launchpad.net/ubuntu/+source/varnish/6.6.1-1ubuntu0.2
  https://launchpad.net/ubuntu/+source/varnish/6.5.2-1ubuntu0.2
  https://launchpad.net/ubuntu/+source/varnish/6.2.1-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/varnish/5.2.1-1ubuntu0.1