Denial of service in D-Bus

1) Use-after-free

EUVDB-ID: #VU62883

Risk: Low

CVSSv4.0: 1.9 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-35512

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error if two usernames have the same numeric UID. When a set of policy rules references these usernames, D-Bus may free some memory in the heap, which is still used by data structures necessary for the other usernames sharing the UID, which can result in crash.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

D-Bus: 1.10.0 - 1.13.16

CPE2.3

• cpe:2.3:a:freedesktop_org:d-bus:1.10.0:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.2:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.4:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.6:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.8:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.10:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.12:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.14:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.16:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:d-bus:1.10.18:*:*:*:*:*:*:*

External links

https://bugs.gentoo.org/755392
https://bugzilla.redhat.com/show_bug.cgi?id=1909101
https://gitlab.freedesktop.org/dbus/dbus/-/issues/305#note_829128
https://security-tracker.debian.org/tracker/CVE-2020-35512

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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