Buffer overflow in Kerberos 4 KDC program allows remote attackers to cause a denial of service via the localrealm variable in the process_v4

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• cygnus network security project cygnus network securityall versions
• kerbnet project kerbnetall versions
• mit kerberosbefore 4.0
• mit kerberos4.0
• mit kerberos 51.0 and later · up to 1.0.7 inclusive
• mit kerberos 51.1
• mit kerberos 51.1.1

Other highest-scoring records for the same primary product.

• CVE-2000-0548Buffer overflow in Kerberos 4 KDC program allows remote attackers to cause a denial of service via the e_msg variable in the kerb_err_reply
  21Monitor
• CVE-2000-0546Buffer overflow in Kerberos 4 KDC program allows remote attackers to cause a denial of service via the lastrealm variable in the set_tgtkey
  21Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1char buf[256];2memcpy(buf, pkt->data, pkt->len);

1char buf[256];2if (pkt->len > sizeof(buf)) {3  return -EINVAL;4}5memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.