CVE-2019-15691

Exp

TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Published: 2019-12-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-15691 is rated High Exploit Risk (76.6/100): CVSS High severity, with high exploitation likelihood (EPSS 4.72%, 91th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.04% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2019-15691

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-15691

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 2026-06-15 3.68% 4.72% +1.04%
2 2026-04-01 3.87% 3.68% -0.19%
3 2025-11-21 — 3.87% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-15691

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
 1.2 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/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:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2019-15691

OS Trackers for CVE-2019-15691

vendor priority summary link
debian not yet assigned CVE-2019-15691 not yet assigned priority: Debian including 1 source packages (tigervnc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-15691
gentoo normal CVE-2019-15691: 1 GLSA(s) (202407-14), 1 atom(s) (net-misc/tigervnc); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-15691
redhat medium — https://access.redhat.com/security/cve/CVE-2019-15691
suse high CVE-2019-15691 severity important: SUSE including 316 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 429 product×package rows across 69 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-SAP-BYOS, … (69 product lines)): Known Affected 231, Fixed 198. https://www.suse.com/security/cve/CVE-2019-15691/
ubuntu medium CVE-2019-15691 medium priority: Ubuntu including 1 source packages (tigervnc), 18 status rows across 18 suites (bionic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 12, DNE 2, ignored 2, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2019-15691

Affected software / configurations for CVE-2019-15691

Vendor Product Version Raw CPE
tigervnc tigervnc < 1.10.1 cpe:2.3:a:tigervnc:tigervnc:*:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

References for CVE-2019-15691

cvelogic Threat Intelligence