CVE-2021-27103: Accellion FTA Server-Side Request Forgery (SSRF) Vulnerability
Affects Accellion FTASource CISA KEV
Exploited in the wild · used in ransomware campaigns · KEV due 17 Nov 2021 · 11% EPSS : apply the vendor's fix or mitigations to Accellion FTA now.
Data as of 10/24/2026, 22:15:59 UTC
- Exploitation
Actively exploited – in CISA KEV since 11/03/2021
- KEV deadline
- 11/17/2021 US federal agencies must patch by this date; a sensible deadline for everyone else.
- Ransomware
- Used in ransomware campaigns
- EPSS
- 11.4% chance of exploitation in 30 days – higher than 96% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWhat to do
CISA required action
Apply updates per vendor instructions.
Description
Accellion FTA contains a server-side request forgery (SSRF) vulnerability exploited via a crafted POST request to wmProgressstat.html.
Weaknesses
- CWE-918Server-Side Request Forgery (SSRF) (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.