CVE-2016-9942

Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or…

published December 31, 2016

CVSS
—
EPSS
4%
Percentile
90.0
In the wild
Unconfirmed
What it is

⚠️ A crafty buffer overflow in LibVNCClient could lead to application crashes or even arbitrary code execution! 😱 Think of it as a restaurant where a chef accepts a delivery of ingredients that’s far more than what the recipe calls for. When the kitchen tries to cook with that overflowing order, it might just cause a giant mess and shut down the whole operation! An attacker could send a specially crafted FramebufferUpdate message, potentially crashing the application or opening the door for them to run malicious code at will. Even if it’s not being actively exploited yet, it’s like leaving a back door ajar in your home — you never know who might wander in!

Put simply

Think of it as a restaurant where a chef accepts a delivery of ingredients that’s far more than what the recipe calls for. When the kitchen tries to cook with that overflowing order, it might just cause a giant mess and shut down the whole operation! This vulnerability arises from a heap-based buffer overflow in the ultra.c component of LibVNCClient, where the decompressed length of an LZO payload can exceed specified tile dimensions, leading to memory corruption.

What to do

An attacker could send a specially crafted FramebufferUpdate message, potentially crashing the application or opening the door for them to run malicious code at will. Even if it’s not being actively exploited yet, it’s like leaving a back door ajar in your home — you never know who might wander in! To mitigate this issue, upgrade LibVNCServer and LibVNCClient to version 0.9.11 or higher, ensuring that you're not running an outdated version. Make sure to regularly audit your dependencies to avoid similar vulnerabilities in the future! You've got this! Stay proactive, and with these updates, you'll keep your application safe and sound! 🛡️

The record
Technical detail
CVSS
Not scored
CVSS v4.0
Not supplied
EPSS
0.03820 · 90.0th percentile
Published
2016-12-31T18:00Z
EPSS history
Timeline
  • 31 DEC 18:00Z
    Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or…
    cvelistv5