CVE-2016-8581
CWE-79Published: October 28, 2016· Updated: Jun 17, 2026
Official Description
A persistent XSS vulnerability exists in the User-Agent header of the login process of AlienVault OSSIM and USM before 5.3.2 that allows an attacker to steal session IDs of logged in users when the current sessions are viewed by an administrator.
Technical Analysis
CVE-2016-8581 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
A proof-of-concept (PoC) exploit exists for CVE-2016-8581. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2016-8581 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts