Out-of-bounds read in xen (Alpine package)

1) Out-of-bounds read

EUVDB-ID: #VU31985

Risk: Low

CVSSv4.0: 2 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2017-7228

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

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

An issue (known as XSA-212) was discovered in Xen, with fixes available for 4.8.x, 4.7.x, 4.6.x, 4.5.x, and 4.4.x. The earlier XSA-29 fix introduced an insufficient check on XENMEM_exchange input, allowing the caller to drive hypervisor memory accesses outside of the guest provided input/output arrays.

Mitigation

Install update from vendor's website.

Vulnerable software versions

xen (Alpine package): 4.4.1-r0 - 4.5.5-r0

CPE2.3

• cpe:2.3:a:alpine:xen_alpine_package:4.4.1-r0:*:*:*:*:alpine_linux:*:3.0
• cpe:2.3:a:alpine:xen_alpine_package:4.4.1-r6:*:*:*:*:alpine_linux:*:3.0
• cpe:2.3:a:alpine:xen_alpine_package:4.4.1-r7:*:*:*:*:alpine_linux:*:3.0

External links

https://git.alpinelinux.org/aports/commit/?id=2aae6d20dcc445e55f3afde8a9c1c91f9bb4b7f5
https://git.alpinelinux.org/aports/commit/?id=aa5f8776542923a6004a10095d7c75435c70d3df
https://git.alpinelinux.org/aports/commit/?id=5a58568f86fb352acf6c7598f8c7fdf05749676a
https://git.alpinelinux.org/aports/commit/?id=abd894aa9e7936d2fab2956aef4da42c08d8874a
https://git.alpinelinux.org/aports/commit/?id=da85ca277a6878be7b6a40d6904d52c522ed214d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.