FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.20.1, the RDPEAR’s NDR array reader does not perform bounds checking on the on-wire element count. This oversight allows it to write past the heap buffer allocated from hints, resulting in a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in version 3.20.1.
With a CVSS score of 6.8, this vulnerability is classified as medium severity. The risk to organizations includes potential data leakage and system instability due to the high impact on confidentiality, integrity, and availability of the affected systems.
Currently, there is no public exploit confirmed for this vulnerability. However, its nature requires immediate attention to prevent any potential exploitation. Organizations should prioritize patching immediately.
The vulnerability was published on January 14, 2026, which emphasizes the urgency for organizations to act quickly and mitigate any associated risks.
Vulnerability Details
The vulnerability allows an attacker to exploit the flaw by sending specially crafted packets to the vulnerable FreeRDP versions. The CVSS 3.1 score indicates a critical potential risk, highlighting the necessity for immediate remediation.
The affected product is FreeRDP, version prior to 3.20.1. As part of remediation, organizations are advised to upgrade to the latest version to mitigate this risk.
Technical Analysis
The root cause of this vulnerability lies in the failure of the NDR array reader to perform bounds checking on the element count. This leads to a heap buffer overflow, which can be exploited remotely by attackers without any required privileges or user interaction.
The attack vector is through the network, with high complexity due to the requirement for crafted packets. The vulnerability impacts confidentiality, integrity, and availability, making it critical for organizations to address.
Risk & Impact Analysis
Risk to organizations includes potential unauthorized access to sensitive data and disruptions in service. The vulnerability's nature could allow for significant impacts on operational integrity, thus organizations should address in their priority patch cycle.
The medium CVSS score reflects a moderate urgency for remediation, advising organizations to schedule patching efforts promptly to protect their systems.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable version of FreeRDP is any version prior to 3.20.1. Organizations should upgrade to this version or later to mitigate the risk.
Mitigation & Remediation
Organizations should patch to version 3.20.1 or later. In cases where immediate patching is not feasible, consider implementing configuration hardening and network controls to limit exposure.
For further assistance, organizations can refer to our penetration testing services.
Detection Guidance
Organizations should monitor logs for unusual activities related to remote desktop sessions and ensure that any behavioral anomalies are investigated promptly.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability highlights the need for rigorous security practices in software development. It serves as a reminder for security teams to regularly conduct audits of their applications to identify and mitigate similar vulnerabilities.
For further reading, organizations can explore our guides on penetration testing methodology and vulnerability management programs to strengthen their security posture.
Additionally, the evolution of security threats necessitates a proactive approach, as seen in our coverage of API penetration testing strategies.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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