#VU103666 Input validation error in Cisco AsyncOS for Secure Web Appliance - CVE-2025-20183

Vulnerability identifier: #VU103666

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-20183

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco AsyncOS for Secure Web Appliance
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to improper handling of a crafted range request header in a policy-based Cisco Application Visibility and Control (AVC) implementation. A remote attacker can send a specially crafted HTTP request to evade the antivirus scanner and download a malicious file onto the endpoint.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco AsyncOS for Secure Web Appliance: 14.0 - 15.2

---

External links
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-swa-range-bypass-2BsEHYSu

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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