An easily exploitable flaw exists that could enable an anonymous attacker to cause a denial of service on many common FTP server platforms, according to a report published by SecurityReason.
The vulnerability affects a wide range of FTP servers, including those by OpenBSD (V 4.7), NetBSD (V 5.0.2), FreeBSD (V 7.3/8.1), Oracle’s Sun Solaris 10 and GNU Libc, used by some leading software vendors, including HP, Adobe and Apple.The vulnerability is in the glob() function, which is used to enable wild card searches by file names. When exploited the hole can cause servers to become slow, unresponsive and even crash.
According to the report from Maksymilian Arciemowicz, a security researcher with SecurityReason, the error boils down to a problem with GLOB_LIMIT, a component created in 2001 to help reduce memory used by glob(). The faulty component can tie up system memory when it is presented with errant patterns. Arciemowicz said well trafficked sites such as ftp.openbsd.org, ftp.netbsd.org, ftp.freebsd.org, ftp.adobe.com, ftp.hp.com and ftp.sun.com are all vulnerable to denial of service attacks using the glob() function.
Those sites often allow anonymous logins, making attacks even easier.Unlike well known FTP attacks like Gumblar, which remotely steals credentials, the GLOB flaw does not allow remote code to be executed on the affected system and does not appear to be widespread. A patch has yet to be issued. H Security has the full story on the flaw.