Linux Kernel up to 5.13.3 nfs posix_acl_create memory leak

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5.5	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 5.13.3. Affected by this issue is the function posix_acl_create of the component nfs. Such manipulation leads to memory leak. This vulnerability is listed as CVE-2021-47320. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.13.3. It has been rated as critical. Affected by this issue is the function posix_acl_create of the component nfs. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: nfs: fix acl memory leak of posix_acl_create() When looking into another nfs xfstests report, I found acl and default_acl in nfs3_proc_create() and nfs3_proc_mknod() error paths are possibly leaked. Fix them in advance.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-47320 since 05/21/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 234107 (Ubuntu 14.04 LTS / 16.04 LTS : Linux kernel vulnerabilities (USN-7429-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.134, 5.10.52, 5.12.19 or 5.13.4 eliminates this vulnerability. Applying the patch 2e3960f276b4/cef9d9acb7c8/8a2b308a54c5/0704f617040c/d0b32dc1409f/4b515308ab87/c8fc86e9df6a/687cf32865b2/1fcb6fcd74a2 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (234107). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.4.275
• 4.9.275
• 4.14.239
• 4.19.197
• 5.4.133
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.10.37
• 5.10.38
• 5.10.39
• 5.10.40
• 5.10.41
• 5.10.42
• 5.10.43
• 5.10.44
• 5.10.45
• 5.10.46
• 5.10.47
• 5.10.48
• 5.10.49
• 5.10.50
• 5.10.51
• 5.12.0
• 5.12.1
• 5.12.2
• 5.12.3
• 5.12.4
• 5.12.5
• 5.12.6
• 5.12.7
• 5.12.8
• 5.12.9
• 5.12.10
• 5.12.11
• 5.12.12
• 5.12.13
• 5.12.14
• 5.12.15
• 5.12.16
• 5.12.17
• 5.12.18
• 5.13.0
• 5.13.1
• 5.13.2
• 5.13.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 234107
Nessus Name: Ubuntu 14.04 LTS / 16.04 LTS : Linux kernel vulnerabilities (USN-7429-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.4.276/4.9.276/4.14.240/4.19.198/5.4.134/5.10.52/5.12.19/5.13.4
Patch: 2e3960f276b4/cef9d9acb7c8/8a2b308a54c5/0704f617040c/d0b32dc1409f/4b515308ab87/c8fc86e9df6a/687cf32865b2/1fcb6fcd74a2

Timelineinfo

05/21/2024 🔍
05/21/2024 +0 days 🔍
05/21/2024 +0 days 🔍
04/10/2025 +324 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47320 (🔍)
GCVE (CVE): GCVE-0-2021-47320
GCVE (VulDB): GCVE-100-265508

Entryinfo

Created: 05/21/2024 18:16
Updated: 04/10/2025 11:24
Changes: 05/21/2024 18:16 (58), 12/24/2024 17:47 (12), 04/10/2025 11:24 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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