PT-2021-4999 · Cisco · Cisco Ftd

Published 2021-10-27 · Updated 2021-10-29 · CVE-2021-34781

Positive Technologies (AI Summary)

CVSS v3.1

8.6

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Cisco Firepower Threat Defense (FTD) Software (affected versions not specified)

Description The issue is related to the processing of SSH connections for multi-instance deployments of Cisco Firepower Threat Defense (FTD) Software. It is due to a lack of proper error handling when an SSH session fails to be established. An attacker could exploit this by sending a high rate of crafted SSH connections to the instance, potentially causing resource exhaustion and a denial of service (DoS) condition on the affected device. The device must be manually reloaded to recover.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Buffer Overflow

Improper Handling of Exceptional Conditions

Weakness Enumeration

CWE-119

CWE-755

Related Identifiers

BDU:2021-05764

CVE-2021-34781

Affected Products

Cisco Ftd

References · 6

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-rUDseW3r · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-05764 · Security Note
• https://osv.dev/vulnerability/CVE-2021-34781 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34781 · Security Note
• https://t.me/cibsecurity/31313 · Telegram Post
• https://t.me/cvenotify/22514 · Telegram Post