CVE-2021-4206: debian debian_linux Integer Overflow or Wraparound

Vulnerability summary

CVE-2021-4206 is a high (CVSS 8.2) Integer Overflow or Wraparound vulnerability in debian debian_linux. EPSS estimates a 0.83% chance of exploitation in the next 30 days, higher than 57.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 29-04-2022
   PublishedVulnerability first disclosed.
2. 21-03-2025
   Last modifiedVulnerability information updated.

Description

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
• CWE-120Buffer Copy without Checking Size of InputThe product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
• CWE-131Incorrect Calculation of Buffer SizeThe product does not correctly calculate the size to be used when allocating a buffer.