Medium severity5.3NVD Advisory· Published Oct 27, 2021· Updated Aug 11, 2026

CVE-2021-34787

Description

A vulnerability in the identity-based firewall (IDFW) rule processing feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass security protections. This vulnerability is due to improper handling of network requests by affected devices configured to use object group search. An attacker could exploit this vulnerability by sending a specially crafted network request to an affected device. A successful exploit could allow the attacker to bypass access control list (ACL) rules on the device, bypass security protections, and send network traffic to unauthorized hosts.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Cisco Systems, Inc./Cisco Adaptive Security Appliance2 versions
cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*range: <9.8.4.40
- cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*range: >=9.9.0,<9.12.4.25
Cisco Systems, Inc./Secure Firewall Threat Defense
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
Range: <6.4.0.13
Cisco Systems, Inc./Asa 5505 Firmware2 versions
cpe:2.3:o:cisco:asa_5505_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5505_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5505_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5512 X Firmware2 versions
cpe:2.3:o:cisco:asa_5512-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5512-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5512-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5515 X Firmware2 versions
cpe:2.3:o:cisco:asa_5515-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5515-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5515-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5525 X Firmware2 versions
cpe:2.3:o:cisco:asa_5525-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5525-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5525-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5545 X Firmware2 versions
cpe:2.3:o:cisco:asa_5545-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5545-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5545-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5555 X Firmware2 versions
cpe:2.3:o:cisco:asa_5555-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5555-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5555-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5580 Firmware2 versions
cpe:2.3:o:cisco:asa_5580_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5580_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5580_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Asa 5585 X Firmware2 versions
cpe:2.3:o:cisco:asa_5585-x_firmware:009.009:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:cisco:asa_5585-x_firmware:009.009:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5585-x_firmware:009.012:*:*:*:*:*:*:*
Cisco Systems, Inc./Adaptive Security Appliance (ASA) Softwarellm-fuzzy
Cisco Systems, Inc./Firepower Threat Defense Softwarellm-fuzzy
Cisco Systems, Inc./Adaptive Security Appliance Cx Context Aware Security Softwarecpe-rescue
Range: n/a

Patches

Vulnerability mechanics

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-rule-bypass-ejjOgQEYnvdVendor Advisory

News mentions

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