NULL pointer dereference in krb5 (Alpine package)

1) NULL pointer dereference

EUVDB-ID: #VU33342

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 - NULL Pointer Dereference

Exploit availability: No

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

krb5 (Alpine package): 1.15.2-r1 - 1.15.2-r2

CPE2.3

• cpe:2.3:a:alpine:krb5_alpine_package:1.15.2-r1:*:*:*:*:alpine_linux:*:3.6
• cpe:2.3:a:alpine:krb5_alpine_package:1.15.2-r2:*:*:*:*:alpine_linux:*:3.7

External links

https://git.alpinelinux.org/aports/commit/?id=90021f2518697d2787dbe8e0d6fef92096ce0bb4
https://git.alpinelinux.org/aports/commit/?id=a2500ef1ae5455f033e321b01179470b51b624aa
https://git.alpinelinux.org/aports/commit/?id=896ae53d1849faa57ea676acd47332399c11bae7
https://git.alpinelinux.org/aports/commit/?id=9f75bfdaed5cb618df31231e870ec6fed8953927
https://git.alpinelinux.org/aports/commit/?id=cb2ae9a4a2b9b249ba83323406199eb1836f6ded

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.