SB2018082121 - Integer overflow in krb5 (Alpine package)

Description

This security bulletin contains information about 1 vulnerability.

1) Integer overflow (CVE-ID: CVE-2018-5709)

CWE-ID: CWE-190 - Integer overflow

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

The vulnerability allows a remote non-authenticated attacker to manipulate data.

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.

Remediation

Install update from vendor's website.

References

• 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