Permissions, Privileges, and Access Controls in xen (Alpine package)

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU22540

Risk: Low

CVSSv3.1: 6.2 [CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18425

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

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

The vulnerability exists due to missing descriptor table limit checking in x86 PV emulation. A remote unprivileged user of a guest operating system can escalate privileges within the same guest system.

Note, only 32-bit PV guest is affected.

Mitigation

Install update from vendor's website.

Vulnerable software versions

xen (Alpine package): 4.7.0-r0 - 4.10.4-r0

External links

http://git.alpinelinux.org/aports/commit/?id=e42bcd9d2c39e861c980adebf91418ddbe72bd21
http://git.alpinelinux.org/aports/commit/?id=c49084a961893d69e5cdba0b5a8072217ba8be67
http://git.alpinelinux.org/aports/commit/?id=b56efe8db5679b569767cee09b45ce5cd04b942d
http://git.alpinelinux.org/aports/commit/?id=7704a01fec21129dc2f13feb032fb39d8b6a9cb2
http://git.alpinelinux.org/aports/commit/?id=168f974f4f9941c940b1b4a27d1167175018ad92
http://git.alpinelinux.org/aports/commit/?id=1a7ae75cb9ed94f62f9859f8a07a0bc1c5021604
http://git.alpinelinux.org/aports/commit/?id=d9cf7666f5f3aa90dbce9f04bdc7d975284cc530

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.