Incomplete bash code injection fix


The #bashbleed #shellshock fix we got yesterday was only a partial. CVE-7169:

GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of environment variables, which allows remote attackers to write to files or possibly have unknown other impact via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271.

Update bash on your boxes again, or if you can’t, shut down SSH and block it with your firewall rules.

Also, don’t reinstall bash on FreeBSD. Make tcsh your friend, as many on Twitter told me they have yesterday. It really is quite a nice interactive shell, and you’ve always got sh for scripts.

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