libvncserver: Multiple heap out-of-bound writes in VNC client code (Incomplete fix for CVE-2018-20019)
Published Jan 30, 2019
9.8
CRITICALCVSS 3.1
EPSS 3.26%
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 products
No data.
Configuration 1
- < 0.9.12
Configuration 2
- 8.0
Configuration 3
- 14.04
- 16.04
- 18.04
- 18.10
Configuration 4
- 8.0
Configuration 5
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
Configuration 6
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
Configuration 7
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
Configuration 8
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
Configuration 9
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
Configuration 10
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
No data.
Red Hat Enterprise Linux 6
libvncserver
Will not fix
Red Hat Enterprise Linux 7
libvncserver
Affected
Red Hat Enterprise Linux 8
libvncserver
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | libvncserver | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libvncserver | Affected | n/a |
| Red Hat Enterprise Linux 8 | libvncserver | Affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AV:N/AC:L/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (20 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.26% (0.03257) | 87.95th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.23% (0.03230) | 86.59th | v5 (v2026.06.15) |
| Dec 28, 2025 | 10.72% (0.10724) | 93.08th | v4 (v2025.03.14) |
| Dec 27, 2025 | 8.04% (0.08043) | 91.86th | v4 (v2025.03.14) |
| Oct 28, 2025 | 10.90% (0.10905) | 93.05th | v4 (v2025.03.14) |
| Oct 27, 2025 | 8.19% (0.08185) | 91.81th | v4 (v2025.03.14) |
| Oct 1, 2025 | 10.90% (0.10905) | 93.16th | v4 (v2025.03.14) |
| Jul 30, 2025 | 8.19% (0.08185) | 91.82th | v4 (v2025.03.14) |
| Mar 30, 2025 | 10.90% (0.10905) | 92.75th | v4 (v2025.03.14) |
| Mar 29, 2025 | 15.46% (0.15458) | 91.13th | v4 (v2025.03.14) |
| Mar 17, 2025 | 10.90% (0.10905) | 92.86th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.43% (0.00427) | 75.21th | v3 (v2023.03.01) |
| Jun 22, 2024 | 0.43% (0.00427) | 74.51th | v3 (v2023.03.01) |
| Mar 23, 2024 | 0.49% (0.00491) | 75.66th | v3 (v2023.03.01) |
| Jan 24, 2024 | 0.49% (0.00491) | 73.66th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.44% (0.00444) | 70.93th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.54% (0.01537) | 51.33th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.68% (0.02678) | 55.40th | v5 (v2026.06.15) |
| Apr 14, 2021 | 2.48% (0.02476) | 0.00th | v1 |
References (16)
- https://access.redhat.com/security/cve/CVE-2018-20748 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1671407 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf x_refsource_CONFIRMPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/commit/a64c3b37af9a6c8f8009d7516874b8d266b42bae x_refsource_MISCPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/commit/c2c4b81e6cb3b485fb1ec7ba9e7defeb889f6ba7 x_refsource_MISCPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/commit/c5ba3fee85a7ecbbca1df5ffd46d32b92757bc2a x_refsource_MISCPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/commit/e34bcbb759ca5bef85809967a268fdf214c1ad2c x_refsource_MISCPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/issues/273 x_refsource_MISCIssue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2018-20748
- https://usn.ubuntu.com/3877-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/4547-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/4587-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-20748
- https://www.openwall.com/lists/oss-security/2018/12/10/8 x_refsource_MISCExploitMailing ListThird Party Advisory
Change history (0)
No recorded changes yet.