Red Hat Enterprise Linux 7.7 update for screen

1) Improper Neutralization of Argument Delimiters in a Command

EUVDB-ID: #VU50842

Risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-26937

CWE-ID: CWE-88 - Argument Injection or Modification

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to incorrect processing of user-supplied data in the encoding.c file. A remote attacker can pass specially crafted UTF-8 character sequence to the GNU Screen application and perform a denial of service attack or execute arbitrary code on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server - TUS: 7.7

Red Hat Enterprise Linux Server - AUS: 7.7

screen (Red Hat package): before 4.1.0-0.25.20120314git3c2946.el7_7.1

CPE2.3

• cpe:2.3:a:red_hat:red_hat_enterprise_linux_server_-_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
• cpe:2.3:a:red_hat:red_hat_enterprise_linux_server_for_ibm_power_le_-_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:a:red_hat:screen_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2022:1074

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.