shellshock-bash-bug

The bash vulnerability CVE-2014-6271 . Can it affect my CGI perl scripts? How to understand this?

a 夏天 提交于 2019-12-22 01:40:49
问题 Yesterday the problem CVE-2014-6271 was reported which is the BASH Shellshock vulnerability. I am trying to understand if it can affect my server via my Perl CGI scripts. Can my code be affected in a malicious way - what would my code need to do to be affected? What should I check to verify this? 回答1: Yes it affects Perl if your CGI script spawns subshells, e.g., using the system() or open() functions or backticks. See this excellent Red Hat blog post. Note that the blog post is not Red Hat

I'm having difficulty understanding the Shellshock vulnerability verification [duplicate]

☆樱花仙子☆ 提交于 2019-12-20 02:12:10
问题 This question already has answers here : Is the behavior behind the Shellshock vulnerability in Bash documented or at all intentional? (4 answers) Closed 5 years ago . I got this while I was checking for the Shellshock vulnerability: host1:~$ env x='(){ :;}; echo vulnerable' bash -c "echo hello" hello host1:~$ env x='() { :;}; echo vulnerable' bash -c "echo hello" vulnerable hello host1:~$ Weird huh? 回答1: Bash recognizes an environment variable as a function if it starts with precisely the

How does CVE-2014-7169 work? Breakdown of the test code

ε祈祈猫儿з 提交于 2019-12-18 12:22:54
问题 With a bash release which has been patched for shellshock $ bash --version GNU bash, version 3.2.52(1)-release (x86_64-apple-darwin12) Copyright (C) 2007 Free Software Foundation, Inc. $ env x='() { :;}; echo vulnerable' bash -c "echo this is a test" bash: warning: x: ignoring function definition attempt bash: error importing function definition for `x' this is a test another similar exploit still works and has been assigned CVE-2014-7169 $ env X='() { (a)=>\' bash -c "echo date"; cat echo

Bash script does not ssh all the entries of a csv file

折月煮酒 提交于 2019-12-11 08:17:12
问题 I am trying to patch a bunch of CENT OS machines with the latest fix pack. I have the below bash script that takes csv file as a input which has the ip address and password for those machines. The code works fine however, it would only work for the first row it does not seem to be working for the rest of the list as my output.txt only has the entry only for the first row host . patch.sh INPUT=hosts_test.cvs OLDIFS=$IFS IFS=, [ ! -f $INPUT ] && { echo "$INPUT file not found"; exit 99; } while

Can someone explain how this “Shellshock” code works in shell [duplicate]

梦想与她 提交于 2019-12-02 10:38:17
问题 This question already has an answer here : Can someone explain the Shell Shock Bash code? [duplicate] (1 answer) Closed 5 years ago . I read in the news that Shellshock is another bigger vulnerability after Heartbleed. The code to test if our Bash shell is vulnerable or not is: env X="() { :;} ; echo shellshock" /bin/sh -c "echo completed" In detail, how does this code exactly work? What does the code env X="() { :;} ; do? How is it vulnerable and can it be exploited if I am hosting a website

Can someone explain how this “Shellshock” code works in shell [duplicate]

你离开我真会死。 提交于 2019-12-02 04:58:00
This question already has an answer here: Can someone explain the Shell Shock Bash code? [duplicate] 1 answer I read in the news that Shellshock is another bigger vulnerability after Heartbleed . The code to test if our Bash shell is vulnerable or not is: env X="() { :;} ; echo shellshock" /bin/sh -c "echo completed" In detail, how does this code exactly work? What does the code env X="() { :;} ; do? How is it vulnerable and can it be exploited if I am hosting a website in a Linux environment where the shell is vulnerable? nu11p01n73R env x='() { :;}; echo vulnerable' bash -c "echo this is a

Can someone explain the Shell Shock Bash code? [duplicate]

不想你离开。 提交于 2019-12-02 00:39:02
问题 This question already has answers here : Is the behavior behind the Shellshock vulnerability in Bash documented or at all intentional? (4 answers) Closed 5 years ago . I am having problems understanding the following code, which is the Shell Shock 'proof of vulnerability' code. Can someone explain it to me? Specially, this part " () { :;}; " env x='() { :;}; echo vulnerable' bash -c "echo this is a test" 回答1: env x='() { :;}; echo vulnerable' bash -c "echo this is a test" what env does? From

Can someone explain the Shell Shock Bash code? [duplicate]

痴心易碎 提交于 2019-12-01 23:15:42
This question already has an answer here: Is the behavior behind the Shellshock vulnerability in Bash documented or at all intentional? 4 answers I am having problems understanding the following code, which is the Shell Shock 'proof of vulnerability' code. Can someone explain it to me? Specially, this part " () { :;}; " env x='() { :;}; echo vulnerable' bash -c "echo this is a test" env x='() { :;}; echo vulnerable' bash -c "echo this is a test" what env does? From the docs, env runs programs in modified environment env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...] it clear that x is a

I'm having difficulty understanding the Shellshock vulnerability verification [duplicate]

99封情书 提交于 2019-12-01 22:37:46
This question already has an answer here: Is the behavior behind the Shellshock vulnerability in Bash documented or at all intentional? 4 answers I got this while I was checking for the Shellshock vulnerability: host1:~$ env x='(){ :;}; echo vulnerable' bash -c "echo hello" hello host1:~$ env x='() { :;}; echo vulnerable' bash -c "echo hello" vulnerable hello host1:~$ Weird huh? Bash recognizes an environment variable as a function if it starts with precisely the four characters () { , including the space. So env x='(){ :;}; echo vulnerable' doesn't count. This doesn't quite conform to the

Regression: Exported Bash function lost after going through another process

こ雲淡風輕ζ 提交于 2019-12-01 07:35:50
When moving from Ubuntu 14.04 to 16.04, I've noticed several of my Bash scripts failing due to missing exported functions. I wonder whether this is related to the fixes for the Shellshock bug , even though I simply export -f the functions, and not relying on the Bash-internal function representation. The failure does not occur in a direct Bash subshell, only if there's another process in between. For example, Bash invoking awk / Perl / Vim invoking another Bash. Here's an example with Perl: Good $ foo() { echo "foobar"; } $ export -f foo $ export -f; foo foo () { echo "foobar" } declare -fx