GNU Bash Environment Variables Function Parsing Two Vulnerabilities


Description   Michal Zalewski has reported two vulnerabilities in GNU Bash, which can be exploited by malicious people to compromise a vulnerable system.
1) An error in the parser when handling certain script code within environment variables can be exploited to trigger usage of uninitialized data and subsequently e.g. execute arbitrary code via a specially crafted variable value.
2) Another error in the parser when handling certain script code within environment variables can be exploited to inject and execute arbitrary OS shell commands via a specially crafted variable value.
The vulnerabilities are reported in versions 4.3 and prior.
     
Vulnerable Products   Vulnerable Software:
GNU Bash 3.xGNU bash 4.x
     
Solution   Apply mitigation patches available from the vendor, which eliminate the remote vector.
     
CVE   CVE-2014-6278
CVE-2014-6277
     
References   GNU Bash:
http://ftp.gnu.org/gnu/bash/bash-4.3-patches/bash43-027
http://ftp.gnu.org/gnu/bash/bash-4.2-patches/bash42-050
http://ftp.gnu.org/gnu/bash/bash-4.1-patches/bash41-014
http://ftp.gnu.org/gnu/bash/bash-4.0-patches/bash40-041
http://ftp.gnu.org/gnu/bash/bash-3.2-patches/bash32-054
http://ftp.gnu.org/gnu/bash/bash-3.1-patches/bash31-020
http://ftp.gnu.org/gnu/bash/bash-3.0-patches/bash30-019
http://ftp.gnu.org/gnu/bash/bash-2.05b-patches/bash205b-010
Michal Zalewski:
http://lcamtuf.blogspot.com/2014/09/bash-bug-apply-unofficial-patch-now.html
http://lcamtuf.blogspot.com/2014/10/bash-bug-how-we-finally-cracked.html
     
Vulnerability Manager Detection   No
     
IPS Protection  
ASQ Engine alarm Available Since
bash Shellshock dhcp vulnerability CVE-2014-6271
5.0.0
bash Shellshock web vulnerability CVE-2014-6271
5.0.0
bash Shellshock SIP vulnerability CVE-2014-6271
5.0.0
bash Shellshock ftp vulnerability CVE-2014-6271
5.0.0
bash Shellshock smtp vulnerability CVE-2014-6271
5.0.0
     


 
 
 
 
 Risk level 
High 

 Vulnerability First Public Report Date 
2014-10-02 

 Target Type 
Server 

 Possible exploit 
Remote