FreeRDP Memory Exhaustion via Unvalidated PDU Length

FreeRDP before 3.29.0 contains a denial of service vulnerability in the RDPEI server channel handler that fails to validate maximum PDU body length before stream allocation. A malicious RDP client can send a header-only RDPEI message with a large declared body length to force excessive memory allocation on the server.

Casky was already ahead

This CVE exploits attack patterns that Casky's 322matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

FreeRDP versions before 3.29.0 suffer from insufficient input validation in the RDPEI (Remote Desktop Protocol Input Extension) server channel handler. The vulnerability occurs when the server fails to validate the maximum PDU (Protocol Data Unit) body length before allocating memory for incoming messages. An attacker controlling a malicious RDP client can exploit this by sending a specially crafted RDPEI message with only a header but an inflated declared body length, causing the server to attempt excessive memory allocation. This denial of service vulnerability affects any organization running vulnerable FreeRDP servers that accept RDP connections, particularly critical infrastructure, remote desktop service providers, and enterprises relying on FreeRDP for secure remote access.

Casky's 322 mapped security skills leverage Claude's extended reasoning to detect attack patterns associated with this vulnerability across MITRE techniques TA0001 (Reconnaissance) and TA0043 (Resource Development). Practitioners using Casky would identify suspicious RDP connection attempts characterized by anomalous RDPEI protocol sequences—specifically malformed messages with header-body length mismatches. The platform's skills help correlate CWE-20 (Improper Input Validation) patterns with reconnaissance activities where attackers probe RDP services, followed by resource development phases testing memory allocation limits. Detection findings would surface unusual spike patterns in memory consumption during RDPEI channel initialization, protocol parsing failures indicating invalid PDU structures, and client connection profiles attempting multiple oversized message submissions—enabling defenders to distinguish legitimate RDP traffic from exploitation attempts before the denial of service occurs.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

322 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-67296.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

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Casky has 322 skills that investigate the attack patterns behind CVE-2026-67296. Run one and get CVSS-scored findings in 3 minutes.

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