libvncserver: NULL pointer dereference in VNC client code allows for denial of service
Published Dec 19, 2018
7.5
HIGHCVSS 3.0
EPSS 3.26%
Description
LibVNC before commit 4a21bbd097ef7c44bb000c3bd0907f96a10e4ce7 contains null pointer dereference in VNC client code that can result DoS.
Affected products
- Vendor n/a Product LibVNC Defaultn/a
- Version commit 4a21bbd097ef7c44bb000c3bd0907f96a10e4ce7StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | LibVNC | n/a |
|
Configuration 1
- < 0.9.12
Configuration 2
- 14.04
- 16.04
- 18.04
- 18.10
- 8.0
- 9.0
No data.
Red Hat Enterprise Linux 6
libvncserver
Will not fix
Red Hat Enterprise Linux 7
libvncserver
Fix deferred
Red Hat Enterprise Linux 8
libvncserver
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | libvncserver | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libvncserver | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | libvncserver | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/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 (19 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.26% (0.03260) | 87.96th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.26% (0.03260) | 86.72th | v5 (v2026.06.15) |
| Dec 28, 2025 | 3.73% (0.03729) | 87.63th | v4 (v2025.03.14) |
| Dec 27, 2025 | 2.73% (0.02727) | 85.57th | v4 (v2025.03.14) |
| Oct 28, 2025 | 3.79% (0.03788) | 87.55th | v4 (v2025.03.14) |
| Oct 27, 2025 | 2.77% (0.02771) | 85.54th | v4 (v2025.03.14) |
| Oct 1, 2025 | 3.86% (0.03859) | 87.79th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.82% (0.02823) | 84.90th | v4 (v2025.03.14) |
| Mar 29, 2025 | 3.98% (0.03985) | 80.39th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.82% (0.02823) | 85.23th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.95% (0.00948) | 83.83th | v3 (v2023.03.01) |
| Jul 14, 2024 | 0.95% (0.00948) | 83.31th | v3 (v2023.03.01) |
| May 11, 2024 | 1.04% (0.01037) | 83.81th | v3 (v2023.03.01) |
| Dec 13, 2023 | 1.45% (0.01453) | 85.19th | v3 (v2023.03.01) |
| Mar 7, 2023 | 1.56% (0.01563) | 85.14th | 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 | 2.48% (0.02476) | 54.92th | v5 (v2026.06.15) |
| Apr 14, 2021 | 2.48% (0.02476) | 0.00th | v1 |
References (15)
- https://access.redhat.com/security/cve/CVE-2018-20024 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1661132 Issue Tracking
- https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-034-libvnc-null-pointer-dereference/ x_refsource_MISCThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html mailing-listx_refsource_MLIST
- https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2018-20024
- https://security.gentoo.org/glsa/201908-05 vendor-advisoryx_refsource_GENTOO
- https://security.gentoo.org/glsa/202006-06 vendor-advisoryx_refsource_GENTOO
- https://usn.ubuntu.com/3877-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/4547-1/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/4547-2/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/4587-1/ vendor-advisoryx_refsource_UBUNTU
- https://www.cve.org/CVERecord?id=CVE-2018-20024
- https://www.debian.org/security/2019/dsa-4383 vendor-advisoryx_refsource_DEBIANThird Party Advisory
Change history (0)
No recorded changes yet.