Remote memory disclosure when parsing GRE packets in Linux Kernel

1) Out-of-bounds read

EUVDB-ID: #VU5675

Risk: Medium

CVSSv3.1: 8.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H/E:U/RL:W/RC:C]

CVE-ID: CVE-2017-5897

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote unauthenticated attacker to obtain potentially sensitive information.

The vulnerability exists due to boundary error when processing GRE packets in ip6gre_err() function in net/ipv6/ip6_gre.c. A remote attacker can send specially crafted GRE packets to IPv6 interface, trigger out-of-bounds read and obtain memory contents or cause denial of service.

Successful exploitation of the vulnerability may allow an attacker to gain access to potentially sensitive information, stored in RAM, such as passwords, encryption keys, etc.

Mitigation

Install patch from GIT repository:
https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=7892032cfe67f4bde6fc2ee967e45a...

Vulnerable software versions

Linux kernel: 4.0.1 - 4.9.9

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:4.0.9:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.1.38:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.2.8:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.3.6:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.48:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.5.7:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.7.10:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.8.17:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.9.9:*:*:*:*:*:*:*

External links

http://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=7892032cfe67f4bde6fc2ee967e45a...

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.