*** This bug is a security vulnerability *** Public security bug reported:
"The problem with bash's name references Bash 4.3 introduced declare -n ("name references") to mimic Korn shell's nameref feature, which permits variables to hold references to other variables (see FAQ 006 to see these in action). Unfortunately, the implementation used in Bash has some issues. {…} Bash's name reference implementation still allows arbitrary code execution: $ foo() { declare -n var=$1; echo "$var"; } $ foo 'x[i=$(date)]' bash: i=Thu Mar 27 16:34:09 EDT 2014: syntax error in expression (error token is "Mar 27 16:34:09 EDT 2014") It's not an elegant example, but you can clearly see that the date command was actually executed. This is not at all what one wants." source: http://mywiki.wooledge.org/BashFAQ/048 ** Affects: bash (Ubuntu) Importance: Undecided Status: New ** Information type changed from Private Security to Public Security ** Description changed: "The problem with bash's name references Bash 4.3 introduced declare -n ("name references") to mimic Korn shell's nameref feature, which permits variables to hold references to other variables (see FAQ 006 to see these in action). Unfortunately, the implementation used in Bash has some issues. {…} Bash's name reference implementation still allows arbitrary code execution: $ foo() { declare -n var=$1; echo "$var"; } $ foo 'x[i=$(date)]' bash: i=Thu Mar 27 16:34:09 EDT 2014: syntax error in expression (error token is "Mar 27 16:34:09 EDT 2014") It's not an elegant example, but you can clearly see that the date - command was actually executed. This is not at all what one wants. + command was actually executed. This is not at all what one wants." source: http://mywiki.wooledge.org/BashFAQ/048 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1411318 Title: arbitrary code execution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1411318/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs