CVE-2025-24528
📋 TL;DR
This vulnerability in MIT Kerberos 5 allows authenticated attackers to trigger an integer overflow in the kadmind daemon's log handling code, leading to an out-of-bounds write and service crash. Systems running krb5 versions before 1.22 with incremental propagation enabled are affected. The attack requires authentication but can disrupt Kerberos administration services.
💻 Affected Systems
- MIT Kerberos 5 (krb5)
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise if the out-of-bounds write can be controlled to execute arbitrary code, though this would require additional exploitation techniques beyond the described crash.
Likely Case
Denial of service through kadmind daemon crash, disrupting Kerberos administration and potentially authentication services.
If Mitigated
Minimal impact if proper network segmentation and authentication controls limit access to kadmind services.
🎯 Exploit Status
Exploitation requires authentication to kadmind and knowledge of incremental propagation operations. The integer overflow leads to memory corruption that must be carefully controlled for code execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.22 or later
Vendor Advisory: https://github.com/krb5/krb5/commit/78ceba024b64d49612375be4a12d1c066b0bfbd0
Restart Required: Yes
Instructions:
1. Upgrade krb5 to version 1.22 or later. 2. Restart kadmind and KDC services. 3. For Linux distributions, use package manager: 'apt upgrade krb5-admin-server' (Debian/Ubuntu) or 'yum update krb5-server' (RHEL/CentOS).
🔧 Temporary Workarounds
Disable incremental propagation
linuxTemporarily disable incremental KDC propagation to remove the vulnerable code path
Edit /var/lib/krb5kdc/kpropd.acl and remove incremental update entries
Restart kadmind: systemctl restart krb5-admin-server
Restrict kadmind access
linuxLimit network access to kadmind service using firewall rules
iptables -A INPUT -p tcp --dport 749 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 749 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate kadmind services from untrusted networks
- Enforce strong authentication and limit administrative privileges to minimize attack surface
🔍 How to Verify
Check if Vulnerable:
Check krb5 version: krb5-config --version | grep -q '1\.2[0-1]\|1\.1[0-9]\|1\.[0-9]\.[0-9]' && echo 'VULNERABLE'Check Version:
krb5-config --version || kadmin --version || rpm -q krb5-server || dpkg -l | grep krb5Verify Fix Applied:
Verify version is 1.22 or later: krb5-config --version | grep -q '1\.2[2-9]\|1\.[3-9][0-9]' && echo 'PATCHED'📡 Detection & Monitoring
Log Indicators:
- kadmind crash logs in /var/log/krb5kdc.log
- Segmentation fault errors from kadmind process
- Unusual large update requests to kadmind
Network Indicators:
- Multiple connection attempts to TCP port 749 (kadmind) followed by service unavailability
- Abnormal traffic patterns to KDC administration ports
SIEM Query:
source="krb5kdc.log" AND ("segmentation fault" OR "kadmind crashed" OR "update size" > threshold)