CVE-2019-12749
Published: 11 June 2019
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.
Priority
Status
Package | Release | Status |
---|---|---|
dbus Launchpad, Ubuntu, Debian |
upstream |
Needs triage
|
xenial |
Released
(1.10.6-1ubuntu3.4)
|
|
bionic |
Released
(1.12.2-1ubuntu1.1)
|
|
cosmic |
Released
(1.12.10-1ubuntu2.1)
|
|
disco |
Released
(1.12.12-1ubuntu1.1)
|
|
Patches: upstream: https://gitlab.freedesktop.org/dbus/dbus/uploads/25073ca3ccbcd7839d5c0d8224e42d99/0001-auth-Reject-DBUS_COOKIE_SHA1-for-users-other-than-th.patch (1.10.x) upstream: https://gitlab.freedesktop.org/dbus/dbus/uploads/1d0109466b4564df1ad093aad2fcebfa/0001-auth-Reject-DBUS_COOKIE_SHA1-for-users-other-than-th.patch (1.12.x) upstream: https://gitlab.freedesktop.org/dbus/dbus/uploads/10e58a024127b230b142932c79f0a94e/0001-auth-Reject-DBUS_COOKIE_SHA1-for-users-other-than-th.patch (1.13.x) |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.1 |
Attack vector | Local |
Attack complexity | Low |
Privileges required | Low |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | None |
Vector | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |