CVE-2021-27103

What is this vulnerability?

CVE-2021-27103 is categorized as a critical Server-Side Request Forgery (SSRF) flaw with a CVSS base score of 9.8. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

Accellion FTA 9_12_411 and earlier is affected by SSRF via a crafted POST request to wmProgressstat.html. The fixed version is FTA_9_12_416 and later.

This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.

Risk Assessment

Impact on Systems

✅ Unauthorized Data Access: Attackers can bypass authorization controls to access other users' data or administrative endpoints.

✅ Account Takeover: Broken authentication or authorization may enable full account compromise without valid credentials.

✅ API Abuse: Exploiting this vulnerability enables mass data harvesting or destructive operations through unprotected API endpoints.

How to Fix and Mitigate CVE-2021-27103

1. Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
2. Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
3. Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
4. Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.

Defending with Precogs AI

Accellion FTA contains a Server-Side Request Forgery (SSRF) vulnerability in the wmProgressstat endpoint. Attackers send crafted POST requests to force the server to interact with internal systems or extract cloud metadata. Precogs Application Security Module audits network dispatchers for SSRF patterns.

Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.

Start scanning with Precogs →

Vulnerability Code Signature

Attack Data Flow

Vulnerable Code Pattern

// ❌ VULNERABLE: Server-Side Request Forgery
app.get('/proxy', async (req, res) => {
  const targetUrl = req.query.url;
  // Taint sink: unvalidated outbound request
  const response = await fetch(targetUrl);
  res.send(await response.text());
});

Secure Code Pattern

// ✅ SECURE: Allowlist validation
const ALLOWED_DOMAINS = ['api.partner.com'];
app.get('/proxy', async (req, res) => {
  const targetUrl = new URL(req.query.url);
  
  if (!ALLOWED_DOMAINS.includes(targetUrl.hostname)) {
    return res.status(403).send("Domain not allowed");
  }
  
  // Sanitized outbound request
  const response = await fetch(targetUrl.href);
  res.send(await response.text());
});

How Precogs Detects This

Precogs API Security Engine actively detects SSRF vulnerabilities by tracking unvalidated URL sinks and enforcing strict allowlist policies.\n