Full Disclosure mailing list archives
Re: getenv("=A") works (no particular vulnerability)
From: bo0od via Fulldisclosure <fulldisclosure () seclists org>
Date: Sat, 5 Feb 2022 07:10:03 +0000
post it to glibc (there are devs,ticket system, community..) https://www.gnu.org/software/libc/ Askar Safin via Fulldisclosure:
TL;DR: this mail doesn't contain any actual vulnerability, just an idea.
Consider this C code for Linux and glibc:
---------
#define _GNU_SOURCE 1
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
char *new_env[] = {"=A=B", 0};
int
main ()
{
environ = new_env;
printf("%s\n", getenv("=A")); // prints "B"
return 0;
}
---------
This code prints "B". I. e. glibc allows variables starting with "=". It is quite possible such behavior can lead to
various vulnerabilities.
It is possible this list is inappropriate for such message. If so, please, say, where I should post such message next
time.
==
Askar Safin
http://safinaskar.com
https://sr.ht/~safinaskar
https://github.com/safinaskar
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Current thread:
- getenv("=A") works (no particular vulnerability) Askar Safin via Fulldisclosure (Feb 04)
- Re: getenv("=A") works (no particular vulnerability) Andy Bach (Feb 06)
- Re: getenv("=A") works (no particular vulnerability) bo0od via Fulldisclosure (Feb 06)
