Libvncserver
CVE-2016-9941
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, buffer size validation
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 0.84%. |
| Exploit ScenarioDerived | A remote attacker could corrupt memory to execute arbitrary code or crash the application by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
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. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. 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. Affected products include: Libvncserver Project Libvncserver. Version information: before 0.9.11.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)CVE.org
More in Libvncserver
View allAn issue was discovered in LibVNCServer through 0.9.11. Rated critical severity (CVSS 9.8), this vulnerability is remote
The HandleRFBServerMessage function in libvncclient/rfbproto.c in LibVNCServer 0.9.9 and earlier does not check certain
The rfbProcessClientNormalMessage function in libvncserver/rfbserver.c in LibVNCServer 0.9.9 and earlier does not proper
A divide by zero issue was found to occur in libvncserver-0.9.12. Rated high severity (CVSS 7.5), this vulnerability is
The rfbProcessClientNormalMessage function in libvncserver/rfbserver.c in LibVNCServer 0.9.9 and earlier allows remote a
Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a den
LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write vulnerability inside stru
LibVNC before commit a83439b9fbe0f03c48eb94ed05729cb016f8b72f contains multiple heap out-of-bound write vulnerabilities
LibVNC before commit 502821828ed00b4a2c4bef90683d0fd88ce495de contains heap out-of-bound write vulnerability in server c
LibVNC before commit 73cb96fec028a576a5a24417b57723b55854ad7b contains heap use-after-free vulnerability in server code
Integer overflow in the MallocFrameBuffer function in vncviewer.c in LibVNCServer 0.9.9 and earlier allows remote VNC se
Multiple stack-based buffer overflows in the File Transfer feature in rfbserver.c in LibVNCServer 0.9.9 and earlier allo
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