Amazon Linux AMI 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

Update the affected packages:

i686:
    screen-debuginfo-4.0.3-19.7.amzn1.i686
    screen-4.0.3-19.7.amzn1.i686

src:
    screen-4.0.3-19.7.amzn1.src

x86_64:
    screen-debuginfo-4.0.3-19.7.amzn1.x86_64
    screen-4.0.3-19.7.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

CPE2.3

• cpe:2.3:o:amazon_web_services:amazon_linux_ami:*:*:*:*:*:*:*:*

External links

https://alas.aws.amazon.com/ALAS-2021-1492.html

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.