CVE-2020-3117: Cisco Web Security Appliance and Cisco Content Security Management Appliance HTTP Header Injection Vulnerability

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-09-23 · updated 2026-06-17
Weakness: CWE-113

Description

A vulnerability in the API Framework of Cisco AsyncOS for Cisco Web Security Appliance (WSA) and Cisco Content Security Management Appliance (SMA) could allow an unauthenticated, remote attacker to inject crafted HTTP headers in the web server's response. The vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user to access a crafted URL and receive a malicious HTTP response. A successful exploit could allow the attacker to inject arbitrary HTTP headers into valid HTTP responses sent to a user's browser.

Affected products

Cisco Content Security Management Appliance (SMA): before 13.0.0-187 — fixed in 13.0.0-187
Cisco Web Security Appliance (WSA): 11.8.0-382, 12.0.1-268

How to fix

Upgrade to a fixed version: Cisco Content Security Management Appliance (SMA) 13.0.0-187. Check the vendor advisory for mitigations.

References

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