What’s Vulnerable › Vulnerabilities
CVE-2019-20839
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 3.6% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2020-06-17 · updated 2026-06-17
- Weakness: CWE-120
Description
libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.
Affected products
- Canonical Ubuntu Linux: 14.04, 16.04, 18.04, 18.10, 20.04
- Debian Linux: 8.0, 9.0
- Libvnc Project Libvncserver: through 0.9.12
- openSUSE Leap: 15.2
- Siemens Simatic Itc1500 Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
- Siemens Simatic Itc1500 Pro Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
- Siemens Simatic Itc1900 Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
- Siemens Simatic Itc1900 Pro Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
- Siemens Simatic Itc2200 Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
- Siemens Simatic Itc2200 Pro Firmware: from 3.0.0.0 before 3.2.1.0 — fixed in 3.2.1.0
How to fix
Upgrade to a fixed version: Siemens Simatic Itc1500 Firmware 3.2.1.0; Siemens Simatic Itc1500 Pro Firmware 3.2.1.0; Siemens Simatic Itc1900 Firmware 3.2.1.0; Siemens Simatic Itc1900 Pro Firmware 3.2.1.0; Siemens Simatic Itc2200 Firmware 3.2.1.0; Siemens Simatic Itc2200 Pro Firmware 3.2.1.0. Check the vendor advisory for mitigations.
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
- https://github.com/LibVNC/libvncserver/commit/3fd03977c9b35800d73a865f167338cb4d05b0c1
- https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13
- https://lists.debian.org/debian-lts-announce/2020/06/msg00035.html
- https://lists.debian.org/debian-lts-announce/2020/08/msg00045.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/
- https://usn.ubuntu.com/4434-1/
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html
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