=========================================================================Ubuntu Security Notice USN-4898-1
March 31, 2021

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

curl could be made to expose sensitive information over the network.

Software Description:
- curl: HTTP, HTTPS, and FTP client and client libraries

Details:

Viktor Szakats discovered that curl did not strip off user credentials
from referrer header fields. A remote attacker could possibly use this
issue to obtain sensitive information. (CVE-2021-22876)

Mingtao Yang discovered that curl incorrectly handled session tickets when
using an HTTPS proxy. A remote attacker in control of an HTTPS proxy could
use this issue to bypass certificate checks and intercept communications.
This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10.
(CVE-2021-22890)

Update instructions:

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

Ubuntu 20.10:
  curl                            7.68.0-1ubuntu4.3
  libcurl3-gnutls                 7.68.0-1ubuntu4.3
  libcurl3-nss                    7.68.0-1ubuntu4.3
  libcurl4                        7.68.0-1ubuntu4.3

Ubuntu 20.04 LTS:
  curl                            7.68.0-1ubuntu2.5
  libcurl3-gnutls                 7.68.0-1ubuntu2.5
  libcurl3-nss                    7.68.0-1ubuntu2.5
  libcurl4                        7.68.0-1ubuntu2.5

Ubuntu 18.04 LTS:
  curl                            7.58.0-2ubuntu3.13
  libcurl3-gnutls                 7.58.0-2ubuntu3.13
  libcurl3-nss                    7.58.0-2ubuntu3.13
  libcurl4                        7.58.0-2ubuntu3.13

Ubuntu 16.04 LTS:
  curl                            7.47.0-1ubuntu2.19
  libcurl3                        7.47.0-1ubuntu2.19
  libcurl3-gnutls                 7.47.0-1ubuntu2.19
  libcurl3-nss                    7.47.0-1ubuntu2.19

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

References:
  https://ubuntu.com/security/notices/USN-4898-1
  CVE-2021-22876, CVE-2021-22890

Package Information:
  https://launchpad.net/ubuntu/+source/curl/7.68.0-1ubuntu4.3
  https://launchpad.net/ubuntu/+source/curl/7.68.0-1ubuntu2.5
  https://launchpad.net/ubuntu/+source/curl/7.58.0-2ubuntu3.13
  https://launchpad.net/ubuntu/+source/curl/7.47.0-1ubuntu2.19