Ubuntu Security Notice USN-5021-2
January 20, 2022

curl vulnerability

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

- Ubuntu 16.04 ESM


curl could be made to expose sensitive information if it received a
specially crafted input.

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


USN-5021-1 fixed vulnerabilities in curl. This update provides
the corresponding updates for Ubuntu 16.04 ESM.

Original advisory details:

Harry Sintonen and Tomas Hoger discovered that curl incorrectly handled
TELNET connections when the -t option was used on the command line.
Uninitialized data possibly containing sensitive information could be sent
to the remote server, contrary to expectations. (CVE-2021-22898,

Update instructions:

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

Ubuntu 16.04 ESM:
curl 7.47.0-1ubuntu2.19+esm3
libcurl3 7.47.0-1ubuntu2.19+esm3
libcurl3-gnutls 7.47.0-1ubuntu2.19+esm3
libcurl3-nss 7.47.0-1ubuntu2.19+esm3

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

CVE-2021-22898, CVE-2021-22925