An issue was discovered in MIT Kerberos 5 (aka krb5) through 1.16. There is a variable "dbentry->n_key_data" in kadmin/dbutil/dump.c that can store 16-bit data but unknowingly the developer has assigned a "u4" variable to it, which is for 32-bit data. An attacker can use this vulnerability to affect other artifacts of the database as we know that a Kerberos database dump file contains trusted data.

References

• https://nvd.nist.gov/vuln/detail/CVE-2018-5709
• https://github.com/poojamnit/Kerberos-V5-1.16-Vulnerabilities/tree/master/Integer%20Overflow
• https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772@%3Cdev.mina.apache.org%3E