CVE-2021-30141 – CVE-2021-30141 is an authentication bypass vuln... (How to Fix)

Q: What is the severity of CVE-2021-30141?

CVE-2021-30141 has a CVSS score of 7.5 (HIGH). CVE-2021-30141 is an authentication bypass vulnerability in Friendica's user export feature that allows anonymous users to access sensitive functionality. This can lead to excessive memory consumption and potential denial of service. All Friendica instances running versions through 2021.01 are affected.

📋 TL;DR

CVE-2021-30141 is an authentication bypass vulnerability in Friendica's user export feature that allows anonymous users to access sensitive functionality. This can lead to excessive memory consumption and potential denial of service. All Friendica instances running versions through 2021.01 are affected.

💻 Affected Systems

Products:

Friendica

Versions: All versions through 2021.01

Operating Systems: All platforms running Friendica

Default Config Vulnerable: ⚠️ Yes

Notes: The vendor notes that authentication cookies are still required, but the route accessibility to non-logged users creates the vulnerability.

📦 What is this software?

Friendica by Friendica

View all CVEs affecting Friendica →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system resource exhaustion leading to denial of service, potential exposure of user data if combined with other vulnerabilities.

🟠

Likely Case

Denial of service through memory exhaustion, system instability, and potential information disclosure.

🟢

If Mitigated

Minimal impact if proper authentication controls are enforced and resource limits are in place.

🌐 Internet-Facing: HIGH - The vulnerability affects web-accessible endpoints that could be targeted by remote attackers.

🏢 Internal Only: MEDIUM - Internal attackers could still exploit this, but external exposure increases the risk significantly.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

The vulnerability involves accessing a specific endpoint without proper authentication, making exploitation straightforward.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after commit acbcc56754121ba080eac5b6fdf69e64ed7fe453

Vendor Advisory: https://github.com/friendica/friendica/issues/10110

Restart Required: No

Instructions:

1. Update Friendica to version after commit acbcc56754121ba080eac5b6fdf69e64ed7fe453. 2. Apply the patch from the GitHub pull request #10113. 3. Verify the /settings/userexport endpoint now requires proper authentication.

🔧 Temporary Workarounds

Block Anonymous Access to User Export

all

Configure web server to block access to /settings/userexport for unauthenticated users

# For Apache: add to .htaccess
<Location "/settings/userexport">
    Require valid-user
</Location>
# For Nginx: add to server block
location /settings/userexport {
    auth_basic "Restricted";
    auth_basic_user_file /path/to/.htpasswd;
}

🧯 If You Can't Patch

Implement strict rate limiting on the /settings/userexport endpoint
Deploy WAF rules to block suspicious access patterns to user export functionality

🔍 How to Verify

Check if Vulnerable:

Attempt to access /settings/userexport without authentication. If accessible, the system is vulnerable.

Check Version:

Check Friendica version in admin panel or via git log for commit history

Verify Fix Applied:

Verify that /settings/userexport now returns authentication error for unauthenticated requests.

📡 Detection & Monitoring

Log Indicators:

Multiple failed authentication attempts followed by access to /settings/userexport
Unusual memory consumption spikes
Anonymous user access to protected endpoints

Network Indicators:

HTTP requests to /settings/userexport without authentication headers
Unusual traffic patterns to user export functionality

SIEM Query:

source="web_server" AND (uri="/settings/userexport" AND NOT auth_status="success")

📊 Metadata

CVE ID: CVE-2021-30141

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-401

Published: April 5, 2021

Last Updated: November 21, 2024

🔗 References

https://github.com/friendica/friendica/issues/10110 Exploit,Third Party Advisory
https://github.com/friendica/friendica/pull/10113/commits/acbcc56754121ba080eac5b6fdf69e64ed7fe453 Patch,Third Party Advisory
https://github.com/friendica/friendica/issues/10110 Exploit,Third Party Advisory
https://github.com/friendica/friendica/pull/10113/commits/acbcc56754121ba080eac5b6fdf69e64ed7fe453 Patch,Third Party Advisory

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