#VU33342 NULL pointer dereference in Kerberos and Kerberos 5 - CVE-2018-5710

Vulnerability identifier: #VU33342

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-5710

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Kerberos
Server applications / Encryption software
Kerberos 5
Client/Desktop applications / Software for system administration

Vendor: MIT

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error. The pre-defined function "strlen" is getting a "NULL" string as a parameter value in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c in the Key Distribution Center (KDC), which allows remote authenticated users to cause a denial of service (NULL pointer dereference) via a modified kadmin client.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Kerberos: 5-1.1 - 5-1.16

Kerberos 5: 1.3 - 1.17

---

External links
https://github.com/poojamnit/Kerberos-V5-1.16-Vulnerabilities/tree/master/Denial%20Of%20Service(DoS)

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.