Computer Associates has patched four remotely exploitable buffer overflow vulnerabilities in its data backup products that could enable attackers to take control of clients and servers without logging in.
The vulnerabilities affect CA's BrightStor ARCServe Backup, BrightStor Enterprise Backup, Business Protection Suite r2, and Server Protection Suite r2, according to a CA security bulletin issued Thursday.
"All four vulnerabilities are going to be trivial to exploit, and they're all going to result in a non-authenticated user taking control of the client or server, said Pedram Amini, manager of TippingPoint's Security Research Team, which discovered two of the four flaws.
One vulnerability, which affects CA's RPC interface, arises from incorrect handling of data on TCP port 6503, and could be exploited through a specially crafted remote procedure call (RPC) request, said a member of security research firm Livesploit, which discovered the other two flaws, on condition of anonymity.
The RPC protocol, which allows an application running on one PC to execute a subroutine on another computer, was used by the 2003 Blaster worm to shut down Windows PCs without any user interaction.
Another vulnerability exists within CA's Discovery Service, which attempts to detect other BrightStor servers on the network by sending UDP probe messages to the broadcast address. An attacker could exploit each server that replies to these probe messages and compromise multiple computers at the same time, according to the researcher.
Vulnerabilities in backup-related services such as ARCserve have previously been subject to automated exploits that spread quickly, which makes these issues a prime target for worm or other kinds of malicious code, Symantec said.
However, Amini says companies that adhere to security best practices are unlikely to be affected. "Unless your backup systems are exposed to the Internet, this isn't a vulnerability that would be affected by a worm," he said. Instead, the vulnerabilities are more suitable for a targeted attack in which a hacker would penetrate a corporate network and then exploit the flaws in order to gain access to other areas. "Once an attacker does penetrate, this is a great avenue for them to get deeper into the network," he said.
Secunia gave the vulnerabilities a blanket rating of 'moderately critical', or three on a five point scale. However, Symantec considered it far more serious, giving it a severity rating of 10 on a 10 point scale.