// For flags

CVE-2021-20197

binutils: Race window allows users to own arbitrary files

Severity Score

6.3
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

6
*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Se presenta una ventana de carrera abierta cuando se escribe la salida en las siguientes utilidades en GNU binutils versiones 2.35 y anteriores: ar, objcopy, strip, ranlib.&#xa0;Cuando estas utilidades son ejecutadas como un usuario privilegiado (presumiblemente como parte de un script que actualiza binarios entre diferentes usuarios), un usuario sin privilegios puede engañar a estas utilidades para que obtengan la propiedad de archivos arbitrario por medio de un enlace simbólico.

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.

The binutils packages provide a collection of binary utilities for the manipulation of object code in various object file formats. It includes the ar, as, gprof, ld, nm, objcopy, objdump, ranlib, readelf, size, strings, strip, and addr2line utilities. Issues addressed include a buffer overflow vulnerability.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Local
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-12-17 CVE Reserved
  • 2021-03-26 CVE Published
  • 2024-08-03 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-59: Improper Link Resolution Before File Access ('Link Following')
  • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CAPEC
Affected Vendors, Products, and Versions (6)