CVE-2011-4080

The sysrq_sysctl_handler function in kernel/sysctl.c in the Linux kernel before 2.6.39 does not require the CAP_SYS_ADMIN capability to modify the dmesg_restrict value, which allows local users to bypass intended access restrictions and read the kernel ring buffer by leveraging root privileges, as demonstrated by a root user in a Linux Containers (aka LXC) environment.

🔗 References (8)

• secalert@redhathttp://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
• secalert@redhathttp://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=bfdc0b497faa82a0ba2f9dddcf109231dd519fcc
• secalert@redhathttp://www.openwall.com/lists/oss-security/2011/10/26/10
• secalert@redhathttps://github.com/torvalds/linux/commit/bfdc0b497faa82a0ba2f9dddcf109231dd519fcc
• af854a3a-2127-422b-91ae-364da2661108http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
• af854a3a-2127-422b-91ae-364da2661108http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=bfdc0b497faa82a0ba2f9dddcf109231dd519fcc
• af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2011/10/26/10
• af854a3a-2127-422b-91ae-364da2661108https://github.com/torvalds/linux/commit/bfdc0b497faa82a0ba2f9dddcf109231dd519fcc