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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-20183

A vulnerability in a policy-based Cisco Application Visibility and Control (AVC) implementation of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to evade the antivirus scanner and download a…

MEDIUM 5.3EPSS 0.44%

Does this matter?

Lower severity and a low EPSS score (0.44%). Track it; it rarely justifies an emergency change on its own.

Description

A vulnerability in a policy-based Cisco Application Visibility and Control (AVC) implementation of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to evade the antivirus scanner and download a malicious file onto an endpoint.  The vulnerability is due to improper handling of a crafted range request header. An attacker could exploit this vulnerability by sending an HTTP request with a crafted range request header through the affected device. A successful exploit could allow the attacker to evade the antivirus scanner and download malware onto the endpoint without detection by Cisco Secure Web Appliance.

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
0.44% probability · 38th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20
Affected
cisco/asyncos
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 0.44%26 October 202626 October 2026

EPSS 0.4% 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.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.