USN-5021-1: curl vulnerabilities

22 July 2021

Several security issues were fixed in curl.



  • curl - HTTP, HTTPS, and FTP client and client libraries


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,

Harry Sintonen discovered that curl incorrectly reused connections in the
connection pool. This could result in curl reusing the wrong connections.

Update instructions

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

Ubuntu 21.04
Ubuntu 20.04
Ubuntu 18.04

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