CVE-2020-25221 Information

Description

get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit process that can use ptrace() or process_vm_readv() aka CID-9fa2dd946743.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

http://www.openwall.com/lists/oss-security/2020/09/10/4 https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.7 https://git.kernel.org/linus/8891adc61dce2a8a41fc0c23262b681c3ec4b73a https://git.kernel.org/linus/9fa2dd946743ae6f30dc4830da19147bf100a7f2 https://security.netapp.com/advisory/ntap-20201001-0003/ https://www.openwall.com/lists/oss-security/2020/09/08/4

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8