CVE-2021-20197 - Improper Link Resolution Before File Access ('Link Following')

Severity

63%

Complexity

10%

Confidentiality

86%

There is an open race window when writing output in the following utilities in GNU binutils version 2.35 and earlier:ar, objcopy, strip, 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.

CVSS 3.1 Base Score 6.3. CVSS Attack Vector: local. CVSS Attack Complexity: high. CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N).

CVSS 2.0 Base Score 3.3. CVSS Attack Vector: local. CVSS Attack Complexity: medium. CVSS Vector: (AV:L/AC:M/Au:N/C:P/I:P/A:N).

Overview

First reported 3 years ago

2021-03-26 17:15:00

Last updated 3 years ago

2021-05-28 10:15:00

Affected Software

GNU Binutils

Red Hat Enterprise Linux 8.0

8.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1913743

https://sourceware.org/bugzilla/show_bug.cgi?id=26945

https://bugzilla.redhat.com/show_bug.cgi?id=1913743

Issue Tracking, Patch, Third Party Advisory

https://sourceware.org/bugzilla/show_bug.cgi?id=26945

Issue Tracking, Patch, Third Party Advisory

https://security.netapp.com/advisory/ntap-20210528-0009/

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