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Vulnerability details: VCID-v15x-cjwj-fkcb
Vulnerability ID VCID-v15x-cjwj-fkcb
Aliases CVE-2018-20749
Summary LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-787 Out-of-bounds Write
CWE-122 Heap-based Buffer Overflow
System Score Found at
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20749.json
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20749
cvssv3 9.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2018-20749
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2018-20749
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20749.json
https://api.first.org/data/v1/epss?cve=CVE-2018-20749
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20749
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/LibVNC/libvncserver/commit/15bb719c03cc70f14c36a843dcb16ed69b405707
https://github.com/LibVNC/libvncserver/issues/273
https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html
https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html
https://www.openwall.com/lists/oss-security/2018/12/10/8
http://www.securityfocus.com/bid/106825
1671403 https://bugzilla.redhat.com/show_bug.cgi?id=1671403
920941 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=920941
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:*:*:*:*:*:*:*
CVE-2018-20749 https://nvd.nist.gov/vuln/detail/CVE-2018-20749
USN-3877-1 https://usn.ubuntu.com/3877-1/
USN-4547-1 https://usn.ubuntu.com/4547-1/
USN-4587-1 https://usn.ubuntu.com/4587-1/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20749.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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2018-20749
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:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2018-20749
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 0.9182
EPSS Score 0.08185
Published At Aug. 6, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:36:00.818243+00:00 Ubuntu USN Importer Import https://usn.ubuntu.com/4547-1/ 37.0.0