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Vulnerability details: VCID-vsph-1se3-z7a8
Vulnerability ID VCID-vsph-1se3-z7a8
Aliases CVE-2018-21247
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 6.8
Risk 3.4
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-909 Missing Initialization of Resource
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
System Score Found at
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-21247.json
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
epss 0.01288 https://api.first.org/data/v1/epss?cve=CVE-2018-21247
cvssv3.1 7.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 5.0 https://nvd.nist.gov/vuln/detail/CVE-2018-21247
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2018-21247
Reference id Reference type URL
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-21247.json
https://api.first.org/data/v1/epss?cve=CVE-2018-21247
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-15126
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-15127
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20019
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20020
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20021
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20022
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20023
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20024
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-21247
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6307
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13
https://github.com/LibVNC/libvncserver/issues/253
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/
1849886 https://bugzilla.redhat.com/show_bug.cgi?id=1849886
cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
CVE-2018-21247 https://nvd.nist.gov/vuln/detail/CVE-2018-21247
RHSA-2021:1811 https://access.redhat.com/errata/RHSA-2021:1811
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-21247.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2018-21247
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2018-21247
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.78802
EPSS Score 0.01288
Published At Aug. 8, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T10:10:01.838950+00:00 NVD Importer Import https://nvd.nist.gov/vuln/detail/CVE-2018-21247 37.0.0