Vulnerability identifier: #VU44035

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-4080

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 2.6.0 - 2.6.38.8

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External links
http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bfdc0b497faa82a0ba2f9dddcf109231dd519fcc
http://www.openwall.com/lists/oss-security/2011/10/26/10
http://github.com/torvalds/linux/commit/bfdc0b497faa82a0ba2f9dddcf109231dd519fcc

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.