dbus before 1.10.28, 1.12.x before 1.12.16, and 1.13.x before 1.13.12, as used in DBusServer in Canonical Upstart in Ubuntu 14.04 (and in some, less common, uses of dbus-daemon), allows cookie spoofing because of symlink mishandling in the reference implementation of DBUS_COOKIE_SHA1 in the libdbus library. (This only affects the DBUS_COOKIE_SHA1 authentication mechanism.) A malicious client with write access to its own home directory could manipulate a ~/.dbus-keyrings symlink to cause a DBusServer with a different uid to read and write in unintended locations. In the worst case, this could result in the DBusServer reusing a cookie that is known to the malicious client, and treating that cookie as evidence that a subsequent client connection came from an attacker-chosen uid, allowing authentication bypass.

References[email protected]/message/V2CQF37O73VH2JDVX2ILX2KD2KLXLQOU/


Source: MITRE

Published: 2019-06-11

Updated: 2020-08-24

Type: CWE-59

Risk Information


Base Score: 3.6

Vector: AV:L/AC:L/Au:N/C:P/I:P/A:N

Impact Score: 4.9

Exploitability Score: 3.9

Severity: LOW


Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Impact Score: 5.2

Exploitability Score: 1.8

Severity: HIGH