Heap overflow in Cisco Adaptive Security Appliance SSL VPN

1) Heap-based buffer overflow

EUVDB-ID: #VU62665

Risk: Medium

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-20737

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when parsing specific HTTP authentication messages in the handler for HTTP authentication for resources accessed through the Clientless SSL VPN portal. A remote authenticated user can send specially crafted traffic to the device acting as a VPN Gateway, trigger a heap-based buffer overflow and gain access to sensitive information or perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco Adaptive Security Appliance (ASA): 9.7.1 - 9.17.1

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ssl-vpn-heap-zLX3FdX
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCwa33898

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.