CVE-2014-6052
HighSummary
The HandleRFBServerMessage function in libvncclient/rfbproto.c in LibVNCServer version 0.9.9 and earlier does not check certain malloc return values, allowing remote VNC servers to cause application crashes or potentially execute arbitrary code by specifying a large screen size in FramebufferUpdate, ResizeFrameBuffer, or PalmVNCReSizeFrameBuffer messages.
Risk Assessment
This vulnerability can lead to application crashes, affecting service availability. There is also a risk of arbitrary code execution, which can compromise system security.
Recommendation
It is recommended to update LibVNCServer to the latest version that includes security fixes. Additionally, monitoring and restricting access to VNC servers is advisable.
Other vulnerabilities in LibVNCServer
See all- CVE-2014-6051High
Integer overflow in the MallocFrameBuffer function in vncviewer.c in LibVNCServer 0.9.9 and earlier allows remote VNC servers to cause a denial of service (crash) and possibly execute arbitrary code via an advertisement for a large screen size, which triggers a heap-based buffer overflow.
- CVE-2026-32854High
In LibVNCServer versions 0.9.15 and prior, a null pointer dereference vulnerability exists in the httpProcessInput() function in httpd.c. Attackers can send specially crafted HTTP requests to exploit missing validation of strchr() return values in the CONNECT and GET proxy handling paths, causing a denial of service.
- CVE-2026-32853High
LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler. Improper bounds checking in the HandleUltraZipBPP() function allows a malicious VNC server to manipulate subrectangle header counts and read beyond the allocated heap buffer.
Original NVD description (English source)
The HandleRFBServerMessage function in libvncclient/rfbproto.c in LibVNCServer 0.9.9 and earlier does not check certain malloc return values, which allows remote VNC servers to cause a denial of service (application crash) or possibly execute arbitrary code by specifying a large screen size in a (1) FramebufferUpdate, (2) ResizeFrameBuffer, or (3) PalmVNCReSizeFrameBuffer message.