libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.
Priority LOW 39CWE-120Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-120 and the CVSS impact.
Summary
libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.
Why it matters now
EPSS 0.03589 89th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 2 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 22
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:* | up to 0.9.12 | Vulnerable | Libvnc Project |
| cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* | 14.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* | 18.10 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* | 20.04 | Vulnerable | Canonical |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:siemens:simatic_itc1500_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
- cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:* Versions up to 0.9.12 Vulnerable ·Libvnc Project
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* Versions 14.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* Versions 18.10 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* Versions 20.04 Vulnerable ·Canonical
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:siemens:simatic_itc1500_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
Show 12 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:h:siemens:simatic_itc1500:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_itc1500_pro_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_itc1500_pro:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_itc1900_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_itc1900:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_itc1900_pro_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_itc1900_pro:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_itc2200_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_itc2200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_itc2200_pro_firmware:*:*:*:*:*:*:*:* | 3.0.0.0 to before 3.2.1.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_itc2200_pro:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* | 15.2 | Vulnerable | openSUSE |
- cpe:2.3:h:siemens:simatic_itc1500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_itc1500_pro_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_itc1500_pro:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_itc1900_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_itc1900:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_itc1900_pro_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_itc1900_pro:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_itc2200_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_itc2200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_itc2200_pro_firmware:*:*:*:*:*:*:*:* Versions 3.0.0.0 to before 3.2.1.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_itc2200_pro:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* Versions 15.2 Vulnerable ·openSUSE
Remediation
Red Hat 1 advisory
- RHSA-2021:1811 Released 2021-05-18 · Red Hat rating Moderatelibvncserver security update
- Red Hat CodeReady Linux Builder (v. 8) libvncserver-devel-0.9.11-17.el8
- Red Hat Enterprise Linux AppStream (v. 8) libvncserver-0.9.11-17.el8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2021:1811 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2021:1811 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2019-20839
- 2026-10-03 Alias added: GHSA-hff6-p675-x48v
References
Patch 2
Advisory 9
- https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13
- [debian-lts-announce] 20200630 [SECURITY] [DLA 2264-1] libvncserver security update
- FEDORA-2020-37112ac660
- FEDORA-2020-1a4b1c8271
- openSUSE-SU-2020:0988
- openSUSE-SU-2020:1025
- openSUSE-SU-2020:1056
- USN-4434-1
- [debian-lts-announce] 20200828 [SECURITY] [DLA 2347-1] libvncserver security update
Sources
- CVE-2019-20839 · CVE Program
- CVE-2019-20839 · NVD
- FIRST EPSS
- GHSA-hff6-p675-x48v · GitHub Advisory Database · CC BY 4.0
- CVE-2019-20839 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences