SB2026031001 - Multiple DoS vulnerabilities in Cisco ASA and Cisco FTD OSPF implementation
Published: March 10, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Buffer overflow (CVE-ID: CVE-2026-20020)
The vulnerability allows a remote user to perform a denial of service attack.
The vulnerability exists due to a boundary error in the OSPF protocol. A remote user on the local network can send specially crafted OSPF update packets to the system, trigger memory corruption and perform a denial of service attack.
2) Out-of-bounds write (CVE-ID: CVE-2026-20022)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error when OSPF canonicalization debug is enabled. A remote attacker on the local network can send specially crafted OSPF packets to the affected device, trigger an out-of-bounds write and perform a denial of service (DoS) attack.
3) Heap-based buffer overflow (CVE-ID: CVE-2026-20024)
The vulnerability allows a remote user to perform a denial of service attack.
The vulnerability exists due to a boundary error when parsing OSPF packets. A remote user on the local network can send specially crafted OSPF packets to the affected device, trigger a heap-based buffer overflow and perform a denial of service attack.
4) Input validation error (CVE-ID: CVE-2026-20025)
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input when processing OSPF link-state update (LSU) packets. A remote user with OSPF secret key can send specially crafted OSPF LSU packets to the device and perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospf-ZH8PhbSW
- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwn69076
- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwo71552
- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwn69081
- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwn69075
- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwn69078