A flaw was found in the bash functionality that evaluates specially formatted environment variables passed to it from another environment. An attacker could use this feature to override or bypass restrictions to the environment to execute shell commands before restrictions have been applied. Certain services and applications allow remote unauthenticated attackers to provide environment variables, allowing them to exploit this issue.

Acknowledgements:

Red Hat would like to thank Stephane Chazelas for reporting this issue.

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 modcgi and modcgid 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.

VMware vCenter Server Appliance (vCSA) 5.5 before Update 2, 5.1 before Update 3, and 5.0 before Update 3c does not properly validate certificates when connecting to a CIM Server on an ESXi host, which allows man-in-the-middle attackers to spoof CIM servers via a crafted certificate.

Unspecified vulnerability in the MySQL Server component in Oracle MySQL 5.5.37 and earlier and 5.6.17 and earlier allows remote authenticated users to affect confidentiality, integrity, and availability via vectors related to SRINFOSC.