libvncserver: Improper initialization in VNC Repeater client code allows for information disclosure
Published Dec 19, 2018
7.5
HIGHCVSS 3.0
EPSS 2.50%
Description
LibVNC before 8b06f835e259652b0ff026898014fc7297ade858 contains CWE-665: Improper Initialization vulnerability in VNC Repeater client code that allows attacker to read stack memory and can be abuse for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and in bypassing ASLR
Affected products
- Vendor n/a Product LibVNC Defaultn/a
- Version commit 8b06f835e259652b0ff026898014fc7297ade858StatusaffectedConstraints-
- 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
- 8.0
- 9.0
Configuration 3
- 14.04
- 16.04
- 18.04
- 18.10
No data.
Red Hat Enterprise Linux 6
libvncserver
Not affected
Red Hat Enterprise Linux 7
libvncserver
Not affected
Red Hat Enterprise Linux 8
libvncserver
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | libvncserver | Not affected | n/a |
| Red Hat Enterprise Linux 7 | libvncserver | Not affected | 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:H/I:N/A:N
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
AV:N/AC:L/Au:N/C:P/I:N/A:N
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 (15 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.50% (0.02495) | 84.10th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.50% (0.02495) | 82.55th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.20% (0.01203) | 77.05th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.24% (0.02243) | 74.21th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.20% (0.01203) | 77.53th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.51% (0.00511) | 77.39th | v3 (v2023.03.01) |
| Jul 14, 2024 | 0.51% (0.00511) | 76.80th | v3 (v2023.03.01) |
| Jun 20, 2024 | 0.56% (0.00560) | 77.74th | v3 (v2023.03.01) |
| May 11, 2024 | 0.57% (0.00573) | 77.81th | v3 (v2023.03.01) |
| Dec 13, 2023 | 0.81% (0.00806) | 79.73th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.90% (0.00899) | 80.24th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.18% (0.01183) | 61.76th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.18% (0.01183) | 35.15th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.86% (0.01865) | 48.06th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.86% (0.01865) | 0.00th | v1 |
References (12)
- https://access.redhat.com/security/cve/CVE-2018-20023 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1661128 Issue Tracking
- https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-033-libvnc-memory-leak/ 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://nvd.nist.gov/vuln/detail/CVE-2018-20023
- https://security.gentoo.org/glsa/201908-05 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/4587-1/ vendor-advisoryx_refsource_UBUNTU
- https://www.cve.org/CVERecord?id=CVE-2018-20023
- https://www.debian.org/security/2019/dsa-4383 vendor-advisoryx_refsource_DEBIANThird Party Advisory
Change history (0)
No recorded changes yet.