libvncserver: uninitialized memory contents are vulnerable to Information Leak
Published Jun 17, 2020
7.5
HIGHCVSS 3.1
EPSS 2.46%
Description
An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function.
Affected products
No data.
Configuration 1
- ≤ 0.9.12
Configuration 2
- 14.04
- 16.04
- 16.04
- 18.04
- 18.10
Configuration 3
- 8.0
- 9.0
Configuration 4
- ≥ 3.0.0.0 · < 3.2.1.0
Running on/with
- n/a
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
No data.
Red Hat Enterprise Linux 8
libvncserver-0:0.9.11-17.el8
Fixed · RHSA-2021:1811
Red Hat Enterprise Linux 6
libvncserver
Not affected
Red Hat Enterprise Linux 7
libvncserver
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | libvncserver-0:0.9.11-17.el8 | Fixed | RHSA-2021:1811 |
| Red Hat Enterprise Linux 6 | libvncserver | Not affected | n/a |
| Red Hat Enterprise Linux 7 | 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
No CVSS v3.0 score for this CVE.
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 2, 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 (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 2.46% (0.02455) | 83.85th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.36% (0.02358) | 81.50th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.14% (0.01137) | 76.43th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.75% (0.02751) | 76.64th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.84% (0.00839) | 73.07th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.22% (0.00216) | 60.46th | v3 (v2023.03.01) |
| Nov 8, 2023 | 0.22% (0.00216) | 59.40th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.44% (0.00442) | 70.86th | 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 | 1.66% (0.01659) | 0.00th | v1 |
References (12)
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2018-21247 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1849886 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf x_refsource_CONFIRMPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13 x_refsource_MISCPatchThird Party Advisory
- https://github.com/LibVNC/libvncserver/issues/253 x_refsource_MISCIssue TrackingThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/ vendor-advisoryx_refsource_FEDORA
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2018-21247
- https://www.cve.org/CVERecord?id=CVE-2018-21247
Change history (0)
No recorded changes yet.