CVE-2021-20197

2021-01-2621:11:10

redhat.com

access.redhat.com

race window

output writing

gnu binutils1

privileged user

unprivileged user

symlink

CVSS2

3.3

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:L/AC:M/Au:N/C:P/I:P/A:N

CVSS3

6.3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

NONE

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

EPSS

Percentile

15.5%

JSON

There is an open race window when writing output in the following utilities in GNU binutils1: ar, objcopy, strip, and ranlib. When these utilities are run as a privileged user (presumably as part of a script updating binaries across different users), an unprivileged user can trick these utilities into getting ownership of arbitrary files through a symlink.