Vulnerability Name:

CVE-2021-34781 (CCN-212272)

Assigned:2021-10-27
Published:2021-10-27
Updated:2021-10-29
Summary:A vulnerability in the processing of SSH connections for multi-instance deployments of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. This vulnerability is due to a lack of proper error handling when an SSH session fails to be established. An attacker could exploit this vulnerability by sending a high rate of crafted SSH connections to the instance. A successful exploit could allow the attacker to cause resource exhaustion, which causes a DoS condition on the affected device. The device must be manually reloaded to recover.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
8.6 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
7.5 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:7.1 High (CVSS v2 Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-755
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-34781

Source: XF
Type: UNKNOWN
cisco-cve202134781-dos(212272)

Source: CCN
Type: Cisco Security Advisory cisco-sa-ftd-dos-rUDseW3r
Cisco Firepower Threat Defense Software SSH Connections Denial of Service Vulnerability

Source: CISCO
Type: Vendor Advisory
20211027 Cisco Firepower Threat Defense Software SSH Connections Denial of Service Vulnerability

Vulnerable Configuration:Configuration 1:
  • cpe:/a:cisco:firepower_management_center_virtual_appliance:6.3.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.4.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.4.0.13:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.5.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.6.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.7.0.3:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:6.7.1:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_management_center_virtual_appliance:7.0.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* (Version >= 6.3.0 and < 6.4.0.13)
  • OR cpe:/a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* (Version >= 6.5.0 and < 6.6.5)
  • OR cpe:/a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* (Version >= 6.7.0 and < 6.7.0.3)
  • OR cpe:/a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* (Version >= 7.0.0 and < 7.0.1)
  • OR cpe:/a:cisco:sourcefire_defense_center:6.3.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.4.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.4.0.13:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.5.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.6.0:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.7.0.3:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:6.7.1:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:sourcefire_defense_center:7.0.0:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    cisco firepower management center virtual appliance 6.3.0
    cisco firepower management center virtual appliance 6.4.0
    cisco firepower management center virtual appliance 6.4.0.13
    cisco firepower management center virtual appliance 6.5.0
    cisco firepower management center virtual appliance 6.6.0
    cisco firepower management center virtual appliance 6.7.0.3
    cisco firepower management center virtual appliance 6.7.1
    cisco firepower management center virtual appliance 7.0.0
    cisco firepower threat defense *
    cisco firepower threat defense *
    cisco firepower threat defense *
    cisco firepower threat defense *
    cisco sourcefire defense center 6.3.0
    cisco sourcefire defense center 6.4.0
    cisco sourcefire defense center 6.4.0.13
    cisco sourcefire defense center 6.5.0
    cisco sourcefire defense center 6.6.0
    cisco sourcefire defense center 6.7.0.3
    cisco sourcefire defense center 6.7.1
    cisco sourcefire defense center 7.0.0
    cisco firepower threat defense software *