CVE-2014-8182
📋 TL;DR
An off-by-one error in OpenLDAP's dnssrv backend allows attackers to crash the slapd service by sending crafted DNS SRV responses. This affects OpenLDAP servers configured to use the dnssrv backend for service discovery. The vulnerability leads to denial of service but does not allow arbitrary code execution.
💻 Affected Systems
- OpenLDAP
📦 What is this software?
Openldap by Openldap
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service for LDAP services, disrupting authentication and directory services for all dependent systems.
Likely Case
Service crash requiring manual restart, causing temporary authentication and directory service disruption.
If Mitigated
No impact if dnssrv backend is not used or proper network controls prevent malicious DNS responses.
🎯 Exploit Status
Exploitation requires ability to send crafted DNS responses to the vulnerable server, which typically requires network access to the DNS infrastructure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: OpenLDAP 2.4.40 and later
Vendor Advisory: https://access.redhat.com/security/cve/cve-2014-8182
Restart Required: Yes
Instructions:
1. Update OpenLDAP to version 2.4.40 or later using your distribution's package manager. 2. Restart slapd service. 3. Verify the update was successful.
🔧 Temporary Workarounds
Disable dnssrv backend
linuxRemove or disable dnssrv backend configuration if not required for your deployment.
# Edit slapd.conf or slapd.d configuration
# Remove or comment out dnssrv backend lines
# Restart slapd: systemctl restart slapd
Network segmentation
linuxRestrict DNS traffic to trusted sources only using firewall rules.
# Example iptables rule to restrict DNS traffic
iptables -A INPUT -p udp --dport 53 -s trusted_dns_server -j ACCEPT
iptables -A INPUT -p udp --dport 53 -j DROP
🧯 If You Can't Patch
- Disable dnssrv backend configuration if not essential for operations
- Implement network controls to restrict DNS traffic to trusted sources only
🔍 How to Verify
Check if Vulnerable:
Check OpenLDAP version and dnssrv backend configuration: 'slapd -V' and review slapd.conf/slapd.d for dnssrv references.Check Version:
slapd -V 2>&1 | head -1Verify Fix Applied:
Verify OpenLDAP version is 2.4.40 or later: 'slapd -V | grep "2\.4\."' and ensure service is running.📡 Detection & Monitoring
Log Indicators:
- slapd crash logs
- segmentation fault errors in system logs
- unexpected slapd service restarts
Network Indicators:
- Unusual DNS traffic to LDAP servers
- DNS responses with malformed SRV records
SIEM Query:
source="syslog" AND ("slapd" AND ("segmentation fault" OR "crash" OR "aborted"))🔗 References
- https://access.redhat.com/security/cve/cve-2014-8182
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2014-8182
- https://bugzilla.suse.com/show_bug.cgi?id=CVE-2014-8182
- https://security-tracker.debian.org/tracker/CVE-2014-8182
- https://access.redhat.com/security/cve/cve-2014-8182
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2014-8182
- https://bugzilla.suse.com/show_bug.cgi?id=CVE-2014-8182
- https://security-tracker.debian.org/tracker/CVE-2014-8182
