CVE-2019-15691

tigervnc: Stack use-after-return due to incorrect usage of stack memory in ZRLEDecoder

Severity Score

7.2

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

TigerVNC versiones anteriores a 1.10.1, es vulnerable al uso de la pila previo al retorno, que se presenta debido a un uso incorrecto de la memoria de pila en ZRLEDecoder. Si la rutina de decodificación arroja una excepción, ZRLEDecoder puede intentar acceder a la variable de la pila, que ya ha sido liberada durante el proceso del desempaquetado de la pila. La explotación de esta vulnerabilidad podría resultar potencialmente en una ejecución de código remota. Este ataque parece ser explotable a través de la conectividad de red.

An update that fixes 5 vulnerabilities is now available. This update for tigervnc fixes the following issues. Fixed a use-after-return due to incorrect usage of stack memory in ZRLEDecoder. Fixed a heap-based buffer overflow in CopyRectDecode. Fixed a heap-based buffer overflow in TightDecoder::FilterGradient. Fixed a heap-based buffer overflow, caused by improper error handling in processing MemOutStream. Fixed a stack-based buffer overflow, which could be triggered from CMsgReader::readSetCursor. This update was imported from the SUSE:SLE-15-SP1:Update update project.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

Single

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2019-08-27 CVE Reserved
2019-12-26 CVE Published
2024-08-05 CVE Updated
2024-08-05 First Exploit
2025-06-19 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-672: Operation on a Resource after Expiration or Release
CWE-825: Expired Pointer Dereference

CAPEC

References (6)

URL	Tag	Source
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1	Release Notes

URL	Date	SRC
https://www.openwall.com/lists/oss-security/2019/12/20/2	2024-08-05

URL	Date	SRC
https://github.com/CendioOssman/tigervnc/commit/d61a767d6842b530ffb532ddd5a3d233119aad40	2022-11-09

URL	Date	SRC
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00039.html	2022-11-09
https://access.redhat.com/security/cve/CVE-2019-15691	2020-09-29
https://bugzilla.redhat.com/show_bug.cgi?id=1789908	2020-09-29

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Tigervnc Search vendor "Tigervnc"		Tigervnc Search vendor "Tigervnc" for product "Tigervnc"				< 1.10.1 Search vendor "Tigervnc" for product "Tigervnc" and version " < 1.10.1"		-		Affected
Opensuse Search vendor "Opensuse"		Leap Search vendor "Opensuse" for product "Leap"				15.1 Search vendor "Opensuse" for product "Leap" and version "15.1"		-		Affected