Link following in Linux kernel

1) Link following

EUVDB-ID: #VU28387

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2009-0416

CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The SSL certificate setup program (genSslCert.sh) in Standards Based Linux Instrumentation for Manageability (SBLIM) sblim-sfcb 1.3.2 allows local users to overwrite arbitrary files via a symlink attack on the (1) /var/tmp/key.pem, (2) /var/tmp/cert.pem, and (3) /var/tmp/ssl.cnf temporary files.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.4 - 4.14.84

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:4.4:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.0:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.0-57:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.1:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.2:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.3:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.4:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.5:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.6:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.7:*:*:*:*:*:*:*

External links

https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.85
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.166
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.142

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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