Several vulnerabilities have been found in the Linux command line tool Beep, including a potentially serious issue introduced by a patch for a privilege escalation flaw.
For well over a decade, Beep has been used by developers on Linux to get a computer’s internal speaker to produce a beep. What makes Beep useful for certain programs is the fact that it allows users to control the pitch, duration and repetitions of the sound. The open source application has not received any updates since 2013.
An unnamed researcher discovered recently that Beep versions through 1.3.4 are affected by a race condition that allows a local attacker to escalate privileges to root.
The security hole has been assigned CVE-2018-0492 and it has been sarcastically described as “the latest breakthrough in the field of acoustic cyber security research.” Someone created a dedicated website for it (holeybeep.ninja), a logo, and named it “Holey Beep.”
The individual or individuals who set up the Holey Beep website have also provided a patch, but someone noticed that this fix actually introduces a potentially more serious vulnerability that allows arbitrary command execution.
“The patch vulnerability seems more severe to me, as people apply patches all the time (they shouldn’t do it as root, but people are people),” Tony Hoyle explained in a post on the Debian bug tracker. “It’s concerning that the holeybeep.ninja site exploited an unrelated fault for ‘fun’ without apparently telling anyone.”
Furthermore, reports of other security issues affecting Beep emerged over the weekend, along with claims that the fix is incomplete. Beep is also said to be affected by some integer overflow bugs, and a vulnerability that can be exploited to obtain information about files on a system and conduct unauthorized activities.
“I question whether beep should be saved. It would require someone carefully reviewing the code and effectively become the new upstream. And all that for a tool talking to the PC speaker, which doesn’t exist in most modern systems anyway,” said German researcher and journalist Hanno Böck. “Instead distros should consider not installing it as suid or just killing the package altogether. I heard some distros (suse) replace beep with a simple ‘printf ‘a’ which seems also a safe solution. (although it obviously kills all frequency/length/etc features of original ‘beep’).”
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