CVE-2021-29725 – This vulnerability in IBM Secure External Authe... (How to Fix)

Q: What is the severity of CVE-2021-29725?

CVE-2021-29725 has a CVSS score of 7.5 (HIGH). This vulnerability in IBM Secure External Authentication Server and IBM Secure Proxy allows remote attackers to cause a denial of service by consuming system resources through a resource leak. Affected organizations using vulnerable versions of these IBM security products are at risk of service disruption.

📋 TL;DR

This vulnerability in IBM Secure External Authentication Server and IBM Secure Proxy allows remote attackers to cause a denial of service by consuming system resources through a resource leak. Affected organizations using vulnerable versions of these IBM security products are at risk of service disruption.

💻 Affected Systems

Products:

IBM Secure External Authentication Server
IBM Secure Proxy

Versions: 2.4.3.2, 6.0.1, 6.0.2 for both products

Operating Systems: Not specified - likely multiple platforms supported by IBM

Default Config Vulnerable: ⚠️ Yes

Notes: All deployments of affected versions are vulnerable regardless of configuration.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete service outage of authentication/proxy services, disrupting access to protected resources and potentially cascading to dependent systems.

🟠

Likely Case

Degraded performance or intermittent service interruptions affecting authentication and proxy functionality.

🟢

If Mitigated

Minimal impact with proper network segmentation, rate limiting, and monitoring in place.

🌐 Internet-Facing: HIGH - Remote exploitation capability makes internet-facing instances particularly vulnerable to DoS attacks.

🏢 Internal Only: MEDIUM - Internal attackers could still exploit, but requires network access and may be detected more easily.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Remote exploitation without authentication makes this relatively easy to weaponize, though no public exploit code is confirmed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Apply fixes per IBM advisories - see vendor links for specific patched versions

Vendor Advisory: https://www.ibm.com/support/pages/node/6471577

Restart Required: Yes

Instructions:

1. Review IBM security advisories. 2. Download and apply appropriate patches from IBM Fix Central. 3. Restart affected services. 4. Verify patch application.

🔧 Temporary Workarounds

Network Segmentation

all

Restrict network access to vulnerable servers to trusted sources only

Use firewall rules to limit inbound connections to specific IP ranges

Rate Limiting

all

Implement connection rate limiting to reduce resource consumption attacks

Configure network devices or application firewalls to limit connections per source IP

🧯 If You Can't Patch

Implement strict network access controls and monitor for unusual connection patterns
Deploy additional monitoring and alerting for resource exhaustion indicators

🔍 How to Verify

Check if Vulnerable:

Check installed version against affected versions list: 2.4.3.2, 6.0.1, 6.0.2

Check Version:

Check product documentation for version query commands specific to each IBM product

Verify Fix Applied:

Verify version is updated beyond affected versions and monitor for resource leak symptoms

📡 Detection & Monitoring

Log Indicators:

Unusual increase in connection attempts
Resource exhaustion warnings
Service restart events

Network Indicators:

High volume of connections from single sources
Abnormal traffic patterns to authentication/proxy ports

SIEM Query:

source="ibm-seas" OR source="ibm-proxy" AND (event_type="resource_exhaustion" OR event_type="connection_flood")

📊 Metadata

CVE ID: CVE-2021-29725

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-770

Published: July 15, 2021

Last Updated: November 21, 2024

🔗 References

https://exchange.xforce.ibmcloud.com/vulnerabilities/201102 VDB Entry,Vendor Advisory
https://www.ibm.com/support/pages/node/6471577 Patch,Vendor Advisory
https://www.ibm.com/support/pages/node/6471615 Patch,Vendor Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/201102 VDB Entry,Vendor Advisory
https://www.ibm.com/support/pages/node/6471577 Patch,Vendor Advisory
https://www.ibm.com/support/pages/node/6471615 Patch,Vendor Advisory

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🔗 Related Vulnerabilities

If you're affected by CVE-2021-29725, you might also want to check these:

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Secure External Authentication Server by Ibm

Secure External Authentication Server by Ibm

Secure External Authentication Server by Ibm

Sterling Secure Proxy by Ibm

Sterling Secure Proxy by Ibm

Sterling Secure Proxy by Ibm

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Network Segmentation

Rate Limiting

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities