SB2021111131 - Red Hat Enterprise Linux 8 update for curl 



SB2021111131 - Red Hat Enterprise Linux 8 update for curl

Published: November 11, 2021

Security Bulletin ID SB2021111131
Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) Use of uninitialized variable (CVE-ID: CVE-2021-22898)

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to usage of uninitialized variable in code, responsible for processing TELNET requests when parsing NEW_ENV variables. A remote attacker can force the affected application to connect to a telnet server under attackers control and read up to 1800 bytes from the uninitialized memory on the libcurl client system.

Proof of concept:

curl telnet://example.com -tNEW_ENV=a,bbbbbb (256 'b's)

2) Information disclosure (CVE-ID: CVE-2021-22876)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to libcurl does not strip off user credentials from the URL when automatically populating the Referer: HTTP request header field in outgoing HTTP requests and therefore risks leaking sensitive data to the server that is the target of the second HTTP request.


3) Use of Uninitialized Variable (CVE-ID: CVE-2021-22925)

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to usage of uninitialized variable in code, responsible for processing TELNET requests when parsing NEW_ENV variables. A remote attacker can force the affected application to connect to a telnet server under attackers control and read up to 1800 bytes from the uninitialized memory on the libcurl client system.


Remediation

Install update from vendor's website.