critical
CVE-2018-20748
libvncserver: Multiple heap out-of-bound writes in VNC client code (Incomplete fix for CVE-2018-20019)
In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.
Severity by source
NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat8.8CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by Red Hat (medium), Ubuntu (medium).
Description
LibVNC before 0.9.12 contains multiple heap out-of-bounds write vulnerabilities in libvncclient/rfbproto.c. The fix for CVE-2018-20019 was incomplete.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| debian 11 | libvncserver, veyon | 0.9.11+dfsg-1.3 and 1 more |
| debian 12 | libvncserver, veyon | 0.9.11+dfsg-1.3 and 1 more |
| debian 13 | libvncserver, veyon | 0.9.11+dfsg-1.3 and 1 more |
| debian 14 | libvncserver | 0.9.11+dfsg-1.3 |
| debian 8 | italc, libvncserver | 1:2.0.2+dfsg1-2+deb8u1 and 1 more |
| echo | libvncserver, veyon | 0.9.11+dfsg-1.3 and 1 more |
| Red Hat | libvncserver, libvncserver-devel | no fix listed |
| ubuntu 14.04 | libvncserver | 0.9.9+dfsg-1ubuntu1.4 |
| ubuntu 14.04-ESM | tightvnc | 1.3.9-6.5+deb8u1build0.14.04.1~esm1 |
| ubuntu 16.04 | italc, libvncserver | 1:2.0.2+dfsg1-4ubuntu0.1 and 1 more |
| ubuntu 16.04-ESM | italc, libvncserver | 1:2.0.2+dfsg1-4ubuntu0.1 and 1 more |
| ubuntu 18.04 | italc, libvncserver | 1:3.0.3+dfsg1-3ubuntu0.1 and 1 more |
Show all 24 entries from 14 sources
| Source | Package | Fixed in |
|---|---|---|
| debian 11 | libvncserver | 0.9.11+dfsg-1.3 |
| debian 11 | veyon | 4.1.7+repack1-1 |
| debian 12 | libvncserver | 0.9.11+dfsg-1.3 |
| debian 12 | veyon | 4.1.7+repack1-1 |
| debian 13 | libvncserver | 0.9.11+dfsg-1.3 |
| debian 13 | veyon | 4.1.7+repack1-1 |
| debian 14 | libvncserver | 0.9.11+dfsg-1.3 |
| debian 8 | italc | 1:2.0.2+dfsg1-2+deb8u1 |
| debian 8 | libvncserver | 0.9.9+dfsg2-6.1+deb8u5 |
| echo | libvncserver | 0.9.11+dfsg-1.3 |
| echo | veyon | 4.1.7+repack1-1 |
| Red Hat | libvncserver | no fix listed |
| Red Hat | libvncserver-devel | no fix listed |
| ubuntu 14.04 | libvncserver | 0.9.9+dfsg-1ubuntu1.4 |
| ubuntu 14.04-ESM | tightvnc | 1.3.9-6.5+deb8u1build0.14.04.1~esm1 |
| ubuntu 16.04 | italc | 1:2.0.2+dfsg1-4ubuntu0.1 |
| ubuntu 16.04 | libvncserver | 0.9.10+dfsg-3ubuntu0.16.04.3 |
| ubuntu 16.04-ESM | italc | 1:2.0.2+dfsg1-4ubuntu0.1 |
| ubuntu 16.04-ESM | libvncserver | 0.9.10+dfsg-3ubuntu0.16.04.3 |
| ubuntu 18.04 | italc | 1:3.0.3+dfsg1-3ubuntu0.1 |
| ubuntu 18.04 | libvncserver | 0.9.11+dfsg-1ubuntu1.1 |
| ubuntu 18.04-ESM | italc | 1:3.0.3+dfsg1-3ubuntu0.1 |
| ubuntu 18.04-ESM | libvncserver | 0.9.11+dfsg-1ubuntu1.1 |
| ubuntu 18.10 | libvncserver | 0.9.11+dfsg-1.1ubuntu0.1 |
References
- https://access.redhat.com/security/cve/CVE-2018-20748
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
- https://github.com/LibVNC/libvncserver/commit/a64c3b37af9a6c8f8009d7516874b8d266b42bae
- https://github.com/LibVNC/libvncserver/commit/c2c4b81e6cb3b485fb1ec7ba9e7defeb889f6ba7
- https://github.com/LibVNC/libvncserver/commit/c5ba3fee85a7ecbbca1df5ffd46d32b92757bc2a
- https://github.com/LibVNC/libvncserver/commit/e34bcbb759ca5bef85809967a268fdf214c1ad2c
- https://github.com/LibVNC/libvncserver/issues/273
- https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html
All 18 references
- https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html
- https://nvd.nist.gov/vuln/detail/CVE-2018-20748
- https://ubuntu.com/security/notices/USN-3877-1
- https://ubuntu.com/security/notices/USN-4547-1
- https://ubuntu.com/security/notices/USN-4587-1
- https://usn.ubuntu.com/3877-1/
- https://usn.ubuntu.com/4547-1/
- https://usn.ubuntu.com/4587-1/
- https://www.cve.org/CVERecord?id=CVE-2018-20748
- https://www.openwall.com/lists/oss-security/2018/12/10/8