NULL pointer dereference in Linux kernel

1) NULL pointer dereference

EUVDB-ID: #VU44768

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-2928

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

The befs_follow_link function in fs/befs/linuxvfs.c in the Linux kernel before 3.1-rc3 does not validate the length attribute of long symlinks, which allows local users to cause a denial of service (incorrect pointer dereference and OOPS) by accessing a long symlink on a malformed Be filesystem.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 3.0 - 3.0.101

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:3.0.101:*:*:*:*:*:*:*

External links

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=338d0f0a6fbc82407864606f5b64b75aeb3c70f2
http://securityreason.com/securityalert/8360
http://www.kernel.org/pub/linux/kernel/v3.0/testing/ChangeLog-3.1-rc3
http://www.openwall.com/lists/oss-security/2011/08/19/1
http://www.openwall.com/lists/oss-security/2011/08/19/5
http://www.pre-cert.de/advisories/PRE-SA-2011-06.txt
http://www.securityfocus.com/archive/1/519387/100/0/threaded
http://www.securityfocus.com/bid/49256
http://exchange.xforce.ibmcloud.com/vulnerabilities/69343

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.