Vulnerability in Freedesktop Dbus
CVE-2019-12749
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (46.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Freedesktop Dbus
- Canonical Ubuntu Linux — versions 16.04, 18.04, 18.10
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.openwall.com/lists/oss-security/2019/06/11/2 (Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2019/06/11/2 (mailing-list, Mailing List, Third Party Advisory, Mitigation)
- usn.ubuntu.com/4015-1/ (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4015-2/ (vendor-advisory)
- www.debian.org/security/2019/dsa-4462 (vendor-advisory)
- seclists.org/bugtraq/2019/Jun/16 (mailing-list)
- www.securityfocus.com/bid/108751 (vdb-entry)
- lists.debian.org/debian-lts-announce/2019/06/msg00005.html (mailing-list)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.opensuse.org/opensuse-security-announce/2019-06/msg00059.html (vendor-advisory)
Frequently asked questions
- What is CVE-2019-12749?
- CVE-2019-12749 is a high-severity vulnerability in Freedesktop Dbus, classified under Improper Link Resolution Before File Access. CVSS score: 7.1/10. Published 2019-06-11.
- How severe is CVE-2019-12749?
- High severity. CVSS v3 base score is 7.1 out of 10.
- Is CVE-2019-12749 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.