CVE-2016-9941

Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message containing a subrectangle outside of the client drawing area.

Published: 2016-12-31 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-9941 is rated High Risk (68.9/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.66%). High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-9941

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-31 0.84% 1.66% +0.83%
2 2025-09-03 0.62% 0.84% +0.22%
3 2025-03-30 — 0.62% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9941

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2016-9941

OS Trackers for CVE-2016-9941

vendor priority summary link
alpine — CVE-2016-9941: 1 source package rows (libvncserver); 9 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 9, open 0. https://security.alpinelinux.org/vuln/CVE-2016-9941
debian not yet assigned CVE-2016-9941 not yet assigned priority: Debian including 2 source packages (libvncserver, veyon), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2016-9941
gentoo normal CVE-2016-9941: 1 GLSA(s) (201702-24), 1 atom(s) (net-libs/libvncserver); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-9941
redhat medium — https://access.redhat.com/security/cve/CVE-2016-9941
suse medium CVE-2016-9941 severity moderate: SUSE including 13 source package names (LibVNCServer-0.9.1-159.1, LibVNCServer-devel-0.9.1-159.1, …), 48 product×package rows across 25 product lines (SUSE Linux Enterprise Desktop 12 SP1, SUSE Linux Enterprise Desktop 12 SP2, … (25 product lines)): Fixed 45, Known Not Affected 3. https://www.suse.com/security/cve/CVE-2016-9941/
ubuntu medium CVE-2016-9941 medium priority: Ubuntu including 2 source packages (italc, libvncserver), 10 status rows across 7 suites (bionic, focal, precise, trusty, upstream, xenial, yakkety): released 7, DNE 2, not-affected 1. https://ubuntu.com/security/CVE-2016-9941

Affected software / configurations for CVE-2016-9941

Vendor Product Version Raw CPE
libvncserver_project libvncserver <= 0.9.10 cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*

References for CVE-2016-9941

cvelogic Threat Intelligence