Freerdp — CraftedSignal Threat Feed

Multiple Vulnerabilities in FreeRDP Allow Remote Code Execution and DoS

hello@craftedsignal.io — Tue, 21 Apr 2026 08:04:45 +0000

Multiple vulnerabilities have been identified in FreeRDP, a free remote desktop protocol implementation. An unauthenticated remote attacker can exploit these vulnerabilities to achieve several malicious outcomes. While the specific CVEs and technical details of these vulnerabilities are not disclosed in this brief, the potential impact includes arbitrary code execution, denial-of-service (DoS), data manipulation, and information disclosure. FreeRDP is widely used, so these vulnerabilities have a potentially broad impact.

Attack Chain

The attacker identifies a vulnerable FreeRDP server exposed to the network.
The attacker crafts a malicious RDP request targeting a specific FreeRDP vulnerability.
The vulnerable FreeRDP server processes the malicious request.
If the vulnerability is an arbitrary code execution flaw, the attacker injects and executes malicious code on the server.
The attacker leverages the executed code to gain further access to the system.
The attacker may attempt to escalate privileges.
The attacker could manipulate sensitive data or exfiltrate it.
The attacker could cause a denial-of-service condition, disrupting RDP services.

Impact

Successful exploitation of these FreeRDP vulnerabilities can lead to a range of severe consequences, including complete system compromise through remote code execution. Data manipulation can corrupt critical information, while data exfiltration can lead to significant financial and reputational damage. Denial-of-service attacks can disrupt business operations and impact user productivity. The scope of impact depends on the specific vulnerabilities exploited and the targeted systems.

Recommendation

Monitor RDP traffic for anomalous patterns and unexpected data within RDP sessions using a network intrusion detection system.
Implement rate limiting on RDP connections to mitigate potential denial-of-service attacks.
Review and harden FreeRDP configurations to minimize the attack surface, specifically focusing on disabling unnecessary features.
Deploy the Sigma rules below to your SIEM to detect potential exploitation attempts.

FreeRDP Heap-Buffer-Overflow Vulnerability (CVE-2026-33982)

hello@craftedsignal.io — Mon, 30 Mar 2026 22:16:19 +0000

CVE-2026-33982 is a heap-buffer-overflow READ vulnerability affecting FreeRDP, a widely used open-source implementation of the Remote Desktop Protocol (RDP). The vulnerability exists in versions prior to 3.24.2 and is located within the winpr_aligned_offset_recalloc() function. Specifically, the flaw occurs due to an out-of-bounds read 24 bytes before the allocated buffer, which could be triggered during specific RDP operations involving memory reallocation. Successful exploitation can lead…

Multiple Vulnerabilities in FreeRDP Allow for DoS and Potential Code Execution

hello@craftedsignal.io — Tue, 24 Mar 2026 10:17:27 +0000

Multiple vulnerabilities exist within FreeRDP, a free implementation of the Remote Desktop Protocol (RDP). An unauthenticated, remote attacker can exploit these vulnerabilities to achieve a denial-of-service (DoS) condition on a vulnerable system, or potentially gain the ability to execute arbitrary code. While the specific CVEs are not detailed in this brief, the generic nature of RDP exploitation makes it a high-impact concern. This issue came to light on March 24, 2026, and is a potential risk to any system using FreeRDP if not mitigated by appropriate updates and security practices. Because of the ubiquitous nature of RDP, this poses a significant risk to organizations using affected versions.

Attack Chain

Attacker identifies a vulnerable FreeRDP server exposed to the network.
Attacker establishes an RDP connection to the target server on port 3389 (default).
Attacker sends a series of crafted RDP packets designed to exploit a specific vulnerability in FreeRDP’s processing of session data.
If successful, the exploit triggers a buffer overflow or other memory corruption issue within the FreeRDP process.
The attacker leverages the memory corruption to overwrite critical program data or inject malicious code into the process’s memory space.
The injected code is executed, granting the attacker control over the FreeRDP session or potentially the entire system, depending on the specific vulnerability and the privileges of the FreeRDP process.
Alternatively, the crafted packets could cause the FreeRDP service to crash, resulting in a denial-of-service condition.
The attacker may then attempt to escalate privileges, install malware, or move laterally within the network.

Impact

Successful exploitation can lead to a denial-of-service condition, disrupting remote access services. More critically, attackers may be able to execute arbitrary code, leading to full system compromise. This could allow attackers to steal sensitive data, install ransomware, or use the compromised system as a foothold for further attacks within the network. The number of potentially affected systems is large, given the widespread use of RDP for remote administration and access.

Recommendation

Monitor network connections for suspicious RDP traffic, especially connections originating from unexpected sources; deploy the provided network connection Sigma rule.
Implement network segmentation to limit the exposure of RDP services to only authorized networks and users.
Audit RDP usage for anomalies and suspicious activity, paying close attention to unexpected processes launched by RDP sessions; leverage process creation Sigma rule.
Ensure FreeRDP is updated to the latest version to patch known vulnerabilities.