xrdp is an open source RDP server. Versions through 0.10.5 have an out-of-bounds read vulnerability in the pre-authentication RDP message parsing logic. A remote, unauthenticated attacker can trigger this flaw by sending a specially crafted sequence of packets during the initial connection phase. This vulnerability results from insufficient validation of input buffer lengths before processing dynamic channel communication. Successful exploitation can lead to a denial-of-service (DoS) condition via a process crash or potential disclosure of sensitive information from the service's memory space. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. Versions through 0.10.5 have a heap-based buffer overflow in the EGFX (graphics dynamic virtual channel) implementation due to insufficient validation of client-controlled size parameters, allowing an out-of-bounds write via crafted PDUs. Pre-authentication exploitation can crash the process, while post-authentication exploitation may achieve remote code execution. This issue has been fixed in version 0.10.6. If users are unable to immediately update, they should run xrdp as a non-privileged user (default since 0.10.2) to limit the impact of successful exploitation.

xrdp is an open source RDP server. Versions through 0.10.5 contain a heap-based buffer overflow vulnerability in the NeutrinoRDP module. When proxying RDP sessions from xrdp to another server, the module fails to properly validate the size of reassembled fragmented virtual channel data against its allocated memory buffer. A malicious downstream RDP server (or an attacker capable of performing a Man-in-the-Middle attack) could exploit this flaw to cause memory corruption, potentially leading to a Denial of Service (DoS) or Remote Code Execution (RCE). The NeutrinoRDP module is not built by default. This vulnerability only affects environments where the module has been explicitly compiled and enabled. Users can verify if the module is built by checking for --enable-neutrinordp in the output of the xrdp -v command. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. Versions through 0.10.5 contain an out-of-bounds read vulnerability during the RDP capability exchange phase. The issue occurs when memory is accessed before validating the remaining buffer length. A remote, unauthenticated attacker can trigger this vulnerability by sending a specially crafted Confirm Active PDU. Successful exploitation could lead to a denial of service (process crash) or potential disclosure of sensitive information from the process memory. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. In versions through 0.10.5, the session execution component did not properly handle an error during the privilege drop process. This improper privilege management could allow an authenticated local attacker to escalate privileges to root and execute arbitrary code on the system. An additional exploit would be needed to facilitate this. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. Versions through 0.10.5 contain a heap-based buffer overflow vulnerability in its logon processing. In environments where domain_user_separator is configured in xrdp.ini, an unauthenticated remote attacker can send a crafted, excessively long username and domain name to overflow the internal buffer. This can corrupt adjacent memory regions, potentially leading to a Denial of Service (DoS) or unexpected behavior. The domain_name_separator directive is commented out by default, systems are not affected by this vulnerability unless it is intentionally configured. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. Versions through 0.10.5 allow an authenticated remote user to execute arbitrary commands on the server due to unsafe handling of the AlternateShell parameter in xrdp-sesman. When the AllowAlternateShell setting is enabled (which is the default when not explicitly configured), xrdp accepts a client-supplied AlternateShell value and executes it via /bin/sh -c during session initialization. This results in shell-interpreted execution of unsanitized, user-controlled input. This behavior effectively provides a scriptable remote command execution primitive over RDP within the security context of the authenticated user, occurring prior to normal window manager startup. This can bypass expected session initialization flows and operational assumptions that restrict execution to interactive desktop environments. This issue has been fixed in version 0.10.6.

xrdp is an open source RDP server. In versions through 0.10.5, xrdp does not implement verification for the Message Authentication Code (MAC) signature of encrypted RDP packets when using the "Classic RDP Security" layer. While the sender correctly generates signatures, the receiving logic lacks the necessary implementation to validate the 8-byte integrity signature, causing it to be silently ignored. An unauthenticated attacker with man-in-the-middle (MITM) capabilities can exploit this missing check to modify encrypted traffic in transit without detection. It does not affect connections where the TLS security layer is enforced. This issue has been fixed in version 0.10.6. If users are unable to immediately upgrade, they should configure xrdp.ini to enforce TLS security (security_layer=tls) to ensure end-to-end integrity.

xrdp is an open source RDP server. xrdp before v0.10.5 contains an unauthenticated stack-based buffer overflow vulnerability. The issue stems from improper bounds checking when processing user domain information during the connection sequence. If exploited, the vulnerability could allow remote attackers to execute arbitrary code on the target system. The vulnerability allows an attacker to overwrite the stack buffer and the return address, which could theoretically be used to redirect the execution flow. The impact of this vulnerability is lessened if a compiler flag has been used to build the xrdp executable with stack canary protection. If this is the case, a second vulnerability would need to be used to leak the stack canary value. Upgrade to version 0.10.5 to receive a patch. Additionally, do not rely on stack canary protection on production systems.