CVE-2021-24032

zstd: Race condition allows attacker to access world-readable destination file

Severity Score

4.7

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Beginning in v1.4.1 and prior to v1.4.9, due to an incomplete fix for CVE-2021-24031, the Zstandard command-line utility created output files with default permissions and restricted those permissions immediately afterwards. Output files could therefore momentarily be readable or writable to unintended parties.

A partir de la versión v1.4.1 y anterior a la v1.4.9, debido a una solución incompleta para el CVE-2021-24031, la utilidad de línea de comandos Zstandard creó archivos de salida con permisos predeterminados y restringió esos permisos inmediatamente después. Por lo tanto, los archivos de salida podrían ser momentáneamente legibles o escribibles para personas no deseadas

A flaw was found in zstd. While the final file mode is reflective of the input file, when compressing or uncompressing, the file can temporarily gain greater permissions than the input and potentially leading to security issues (especially if large files are being handled).

*Credits: N/A

CVSS Scores

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-01-13 CVE Reserved
2021-03-04 CVE Published
2023-03-08 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-276: Incorrect Default Permissions
CWE-277: Insecure Inherited Permissions
CWE-281: Improper Preservation of Permissions

CAPEC

References (5)

URL	Tag	Source
https://www.facebook.com/security/advisories/cve-2021-24032	Third Party Advisory

URL	Date	SRC

URL	Date	SRC
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982519	2021-04-28
https://github.com/facebook/zstd/issues/2491	2021-04-28

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2021-24032	2024-05-30
https://bugzilla.redhat.com/show_bug.cgi?id=1928090	2024-05-30

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Facebook Search vendor "Facebook"		Zstandard Search vendor "Facebook" for product "Zstandard"				>= 1.4.1 < 1.4.9 Search vendor "Facebook" for product "Zstandard" and version " >= 1.4.1 < 1.4.9"		-		Affected