CVE-2026-33983

MEDIUM

FreeRDP: Progressive Codec Quant BYTE Underflow - UB + CPU DoS

Title source: cna

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2.

References (2)

[X_Refsource_Confirm] https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4gfm-4p52-h478

[X_Refsource_Misc] https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425

View Writeup ZIP pw:eip

Scores

CVSS v3 6.5

EPSS 0.0005

EPSS Percentile 14.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-190 CWE-252

Status published

Products (2)

freerdp/freerdp < 3.24.2

FreeRDP/FreeRDP < 3.24.2

Published Mar 30, 2026

Tracked Since Mar 31, 2026