CVE-1999-1261 in Rainbow Six
Summary
by MITRE
Buffer overflow in Rainbow Six Multiplayer allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long nickname (nick) command.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/17/2026
The vulnerability identified as CVE-1999-1261 represents a critical buffer overflow flaw within the multiplayer functionality of the game Rainbow Six. This security weakness specifically manifests when the game processes player nicknames through the nick command, creating an opportunity for remote attackers to exploit the system. The buffer overflow occurs due to insufficient input validation and bounds checking within the game's networking code that handles player identification data.
The technical implementation of this vulnerability stems from the game's failure to properly validate the length of nickname data received from network clients. When an attacker sends a maliciously crafted nickname string that exceeds the allocated buffer size, the excess data overflows into adjacent memory locations. This memory corruption can potentially overwrite critical program variables, function return addresses, or other essential runtime data structures. The vulnerability operates at the application layer and requires no authentication or special privileges to exploit, making it particularly dangerous as it can be triggered remotely over the network.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enabling remote code execution. While the primary effect may manifest as game crashes or server instability, the buffer overflow condition creates opportunities for attackers to inject and execute arbitrary code on affected systems. This capability arises because the overflow can overwrite return addresses or function pointers, allowing an attacker to redirect program execution flow. The vulnerability affects the multiplayer server components of Rainbow Six, potentially compromising entire gaming sessions and networked environments where the game is deployed.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and bounds checking within the game's networking code. System administrators should ensure that all networked gaming applications receive regular security updates and patches from vendors. The implementation of network segmentation and access controls can help limit the potential impact of such attacks. Additionally, monitoring network traffic for unusual nickname length patterns may help detect exploitation attempts. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how insufficient input validation can create severe security implications in networked applications. The attack surface for this vulnerability is particularly concerning given that it affects multiplayer gaming environments where multiple players interact over shared networks, potentially providing attackers with persistent access points for further exploitation attempts.