CVE-2020-27986

What is this vulnerability?

CVE-2020-27986 is categorized as a high Missing Authentication for Critical Function flaw with a CVSS base score of 7.5. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

SonarQube 8.4.2.36762 allows remote attackers to discover cleartext SMTP, SVN, and GitLab credentials via the api/settings/values URI. NOTE: reportedly, the vendor's position for SMTP and SVN is "it is the administrator's responsibility to configure it.

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-2020-27986

1. Apply Vendor Patches: Upgrade affected components to their latest, non-vulnerable versions immediately.
2. Implement Input Validation: Ensure all user-supplied data is validated, sanitized, and type-checked before processing.
3. Deploy Runtime Protection: Use Precogs continuous monitoring to detect exploitation attempts in real time.
4. Audit Dependencies: Review and update all third-party libraries and transitive dependencies.

Defending with Precogs AI

SonarQube exposes a dedicated API endpoint without authentication, allowing attackers to access source code and sensitive project metrics. Attackers exploit this to steal intellectual property and identify hardcoded secrets. Precogs API Security Engine maps all endpoints against strict authentication requirements.

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: Missing Authorization (BOLA)
app.get('/api/users/:id/data', async (req, res) => {
  const userId = req.params.id;
  // Taint sink: fetches data for requested ID without verifying ownership
  const data = await db.getUserData(userId);
  res.json(data);
});

Secure Code Pattern

// ✅ SECURE: Strict Resource Authorization
app.get('/api/users/:id/data', requireAuth, async (req, res) => {
  const requestedId = req.params.id;
  const authenticatedId = req.user.id;
  
  // Sanitized validation: check ownership
  if (requestedId !== authenticatedId && !req.user.isAdmin) {
    return res.status(403).json({ error: "Unauthorized access" });
  }
  
  const data = await db.getUserData(requestedId);
  res.json(data);
});

How Precogs Detects This

Precogs API Security Engine comprehensively audits all exposed endpoints to guarantee strict session validation and resource authorization.\n