CVE-2026-33983

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

Published: Mar 30, 2026Updated: Jul 15, 2026 Sources: CVE List NVD BDUCWE-190

6.5MEDIUM

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-190 CWE-252

Affected Products

АО «ИВК»

commercial·RUaka ivk

АЛЬТ СП 10On-premOS

Operating Systems / linux-distro

Free Software Foundation, Inc.

oss-project·USaka free software foundation, fsf

oss-project·US

and 1 more affected products View all →

Exploitability

Official Patch Available

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique

Initial Access

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References

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

github.com

https://altsp.su/obnovleniya-bezopasnosti/

altsp.su

https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425

github.com

and 17 more references View all →

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