CVE-2021-20197

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.

Published: 2021-03-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20197 is rated Low Risk (33.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.31%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20197

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.10% 0.31% +0.20%
2 2025-12-18 0.19% 0.10% -0.09%
3 2025-11-21 — 0.19% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20197

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.3 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.0 5.2 [email protected]
6.3 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.0 5.2 134c704f-9b21-4f2e-91b3-4a467353bcc0
3.3 2.0 LOW
AV:L/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 3.4 4.9 [email protected]

Weakness enumeration for CVE-2021-20197

OS Trackers for CVE-2021-20197

vendor priority summary link
alpine — CVE-2021-20197: 1 source package rows (binutils); 13 state rows across 8 repos (3.10-main, 3.11-main, 3.12-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 13. https://security.alpinelinux.org/vuln/CVE-2021-20197
debian unimportant CVE-2021-20197 unimportant priority: Debian including 1 source packages (binutils), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-20197
gentoo normal CVE-2021-20197: 1 GLSA(s) (202208-30), 2 atom(s) (sys-devel/binutils, sys-libs/binutils-libs); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-20197
redhat medium — https://access.redhat.com/security/cve/CVE-2021-20197
suse medium CVE-2021-20197 severity moderate: SUSE including 441 source package names (0.23.1-12.3:binutils-2.37-7.21.2, 0.23.1-12.3:libctf-nobfd0-2.37-7.21.2, …), 1381 product×package rows across 315 product lines (Container bci/bci-sle15-kernel-module-devel, Container bci/gcc, … (315 product lines)): Fixed 1145, Known Affected 231, Known Not Affected 3, Will Not Fix 2. https://www.suse.com/security/cve/CVE-2021-20197/
ubuntu low CVE-2021-20197 low priority: Ubuntu including 1 source packages (binutils), 9 status rows across 9 suites (bionic, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): ignored 5, not-affected 3, released 1. https://ubuntu.com/security/CVE-2021-20197

Affected software / configurations for CVE-2021-20197

Vendor Product Version Raw CPE
gnu binutils <= 2.35 cpe:2.3:a:gnu:binutils:*:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
netapp cloud_backup — cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
netapp ontap_select_deploy_administration_utility — cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*
netapp solidfire_\&_hci_management_node — cpe:2.3:a:netapp:solidfire_\&_hci_management_node:-:*:*:*:*:*:*:*
broadcom brocade_fabric_operating_system_firmware — cpe:2.3:o:broadcom:brocade_fabric_operating_system_firmware:-:*:*:*:*:*:*:*

References for CVE-2021-20197

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1913743 Issue Tracking Patch Third Party Advisory
https://security.gentoo.org/glsa/202208-30 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210528-0009/ Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=26945 Issue Tracking Patch Third Party Advisory
cvelogic Threat Intelligence