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.
It is unexpected and not allowed to call TTY buffer helpers like ttyinsertflipstring concurrently. This may lead to crashes when ECHOing is enabled and concurrect writers call ptywrite in the meantime. In that case the two writers: the ECHOing from a workqueue and ptywrite from the process race and can overflow the corresponding TTY buffer.
An unprivileged local user could use this flaw to crash the system or, potentially, escalate their privileges on the system.
References: http://seclists.org/oss-sec/2014/q2/243
An access control vulnerability exists in the Applet Rhino Script Engine component of Oracle's Java Runtime Environment allows an attacker to remotely execute arbitrary code.
Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spooldirectory directive.
Description of problem: The handling functions for sending and receiving messages, in rdspagecopyuser(), use the unchecked copyuserinatomic functions without any access checks on user-provided pointers. As a result, by passing a kernel address as an iovec base address in recvmsg-style calls, a local user can overwrite arbitrary kernel memory, which can easily be used to escalate privileges to root.
Introduced via 7875e18e (v2.6.30-rc1).
Acknowledgements:
Red Hat would like to thank Dan Rosenberg of Virtual Security Research for reporting this issue.