CVE-2021-34787
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…
Does this matter?
Lower severity and a low EPSS score (1.04%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 1.04% probability · 64th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-183, CWE-755
- Affected
- cisco/adaptive security appliance · cisco/secure firewall threat defense · cisco/adaptive security appliance software · cisco/asa 5512-x firmware · cisco/asa 5505 firmware · cisco/asa 5515-x firmware · cisco/asa 5525-x firmware · cisco/asa 5545-x firmware · cisco/asa 5555-x firmware · cisco/asa 5580 firmware · cisco/asa 5585-x firmware
- Source
- psirt@cisco.com
EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.