Out-of-bounds write in TigerVNC - CVE-2019-15695
Published: January 3, 2020 / Updated: March 24, 2020
Vulnerability identifier: #VU23908
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-15695
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to insufficient sanitization of PixelFormat. A remote attacker can trigger out-of-bounds write from "CMsgReader::readSetCursor" and execute arbitrary code on the target system.
Affected software
TigerVNC
Amazon Linux AMI
Gentoo Linux
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Opensuse
tigervnc (Red Hat package)
net-misc/tigervnc
Amazon Linux AMI
Gentoo Linux
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Opensuse
tigervnc (Red Hat package)
net-misc/tigervnc
How to mitigate CVE-2019-15695
Install updates from vendor's website.
TigerVNC - update to 1.10.1
tigervnc (Red Hat package) - addressed in versions 1.8.0-21.el7, 1.9.0-14.el8_1
net-misc/tigervnc - update to 1.12.0-r2
tigervnc (Red Hat package) - addressed in versions 1.8.0-21.el7, 1.9.0-14.el8_1
net-misc/tigervnc - update to 1.12.0-r2
External References
- https://github.com/CendioOssman/tigervnc/commit/05e28490873a861379c943bf616614b78b558b89
- https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
- https://www.openwall.com/lists/oss-security/2019/12/20/2
- https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-008-remote-code-execution-on-tigervnc-version-prior-to-1-10-1-2/