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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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Root access vulnerability in glibc library impacts many Linux distros (securityaffairs.com)

submitted 1 year ago by [email protected] to c/[email protected]

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[–] shadowintheday2 96 points 1 year ago (3 children)

"A qsort vulnerability is due to a missing bounds check and can lead to memory corruption. It has been present in all versions of glibc since 1992. "

This one amazes me. Imagine how many vulnerabilities future researchers will discover in ancient software that persisted/persist for decades.

[–] [email protected] 65 points 1 year ago* (last edited 1 year ago) (2 children)

That's not the main part of the article, just a footnote, for anyone wondering.

The flaw resides in the glibc’s syslog function, an attacker can exploit the flaw to gain root access through a privilege escalation.

The vulnerability was introduced in glibc 2.37 in August 2022.

[–] [email protected] 9 points 1 year ago (2 children)

So, it must be with the BSDs too?

[–] [email protected] 1 points 1 year ago (1 children)

Iirc bad does not use glibc, but I'm not very involved with BSD.

[–] [email protected] 4 points 1 year ago

It wouldn't make sense. Glibc is LGPL licensed, not really compatible with the BSD license...

[–] Rustmilian 1 points 1 year ago

BSDs use libc

[–] [email protected] -2 points 1 year ago (2 children)

Wait, why has a compiler system log functionlity?

[–] StefanT 21 points 1 year ago

glibc is a library, gcc is the compiler.

[–] [email protected] 5 points 1 year ago

You are probably confusing the glibc with gcc and g++. Glibc is an implementation of the C standard library, made by GNU (thats where the g in the name comes from).

If you were to look into it, it uses the syscalls to tell the underlying computer system what to do when you call functions, such as printf.

If you want to read more, see here

[–] [email protected] 33 points 1 year ago

C is just crazy. You accidentally forget to put the bounds in a sorting function, and now you are root.

[–] [email protected] 6 points 1 year ago (1 children)

According to the link in the article, the qsort() bug can only be triggered with a non-transitive cmp() function. Would such a cmp function ever be useful?

[–] Giooschi 4 points 1 year ago

You don't necessarily have to write a non-transitive cmp() function willingly, it may happen that you write one without realizing due to some edge cases where it's not transitive.