SB2017052515 - Multiple vulnerabilities in Linux Kernel
Published: May 15, 2017
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Security restrictions bypass (CVE-ID: CVE-2016-9604)
CWE-ID: CWE-732 - Incorrect Permission Assignment for Critical Resource
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local attacker to write arbitrary files on the target system.
The weakness exists due to root can gain direct access to an internal keyring, such as '.dns_resolver' or '.builtin_trusted_keys' upstream, by joining it as its session keyring. A local attacker can bypass module signature verification by adding a new public key of its own devising to the keyring.
2) Information disclosure (CVE-ID: CVE-2015-8944)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local attacker to obtain potentially sensitive information on the target system.
The weakness exists due to weak permissions for /proc/iomem used by the ioresources_init function in kernel/resource.c in the Linux kernel. A local attacker can read arbitrary file on the system.
3) Privilege escalation (CVE-ID: CVE-2016-7097)
CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls
CVSSv4: 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
The vulnerability allows a local attacker to gain elevated privileges on the target system.
The weakness exists due to the setgid bit being preserved during a setxattr call by the filesystem implementation. A local attacker can leverage the existence of a setgid program to gain group privileges.
Successful exploitation of the vulnerability results in privileges escalation.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee8f844e3c5a73b999edf7...
- https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=e758417e7c31b975c862aa55d0ceef28f3c...
- https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.6
- https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.1.37