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Vulnerability details: VCID-221d-v1d2-kqhh
Vulnerability ID VCID-221d-v1d2-kqhh
Aliases CVE-2018-20748
Summary LibVNC before 0.9.12 contains multiple heap out-of-bounds write vulnerabilities in libvncclient/rfbproto.c. The fix for CVE-2018-20019 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-416 Use After Free
System Score Found at
cvssv3 8.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20748.json
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
epss 0.08185 https://api.first.org/data/v1/epss?cve=CVE-2018-20748
cvssv3 8.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2018-20748
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2018-20748
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20748.json
https://api.first.org/data/v1/epss?cve=CVE-2018-20748
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20748
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/LibVNC/libvncserver/commit/a64c3b37af9a6c8f8009d7516874b8d266b42bae
https://github.com/LibVNC/libvncserver/commit/c2c4b81e6cb3b485fb1ec7ba9e7defeb889f6ba7
https://github.com/LibVNC/libvncserver/commit/c5ba3fee85a7ecbbca1df5ffd46d32b92757bc2a
https://github.com/LibVNC/libvncserver/commit/e34bcbb759ca5bef85809967a268fdf214c1ad2c
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
1671407 https://bugzilla.redhat.com/show_bug.cgi?id=1671407
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:*:*:*: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:*:*:*:*:*:*:*
CVE-2018-20748 https://nvd.nist.gov/vuln/detail/CVE-2018-20748
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:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-20748.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:R/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-2018-20748
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-2018-20748
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
2025-07-31T08:36:00.801258+00:00 Ubuntu USN Importer Import https://usn.ubuntu.com/4547-1/ 37.0.0