Linux Kernel up to 4.19.219/5.4.163/5.10.83/5.15.6 rxrpc_lookup_peer memory leak

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 5.5 | $0-$5k | 0.00 |
Summary
A vulnerability labeled as critical has been found in Linux Kernel up to 4.19.219/5.4.163/5.10.83/5.15.6. This impacts the function rxrpc_lookup_peer. The manipulation results in memory leak.
This vulnerability is known as CVE-2021-47538. No exploit is available.
The affected component should be upgraded.
Details
A vulnerability classified as critical has been found in Linux Kernel up to 4.19.219/5.4.163/5.10.83/5.15.6. Affected is the function rxrpc_lookup_peer. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. CVE summarizes:
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix rxrpc_local leak in rxrpc_lookup_peer() Need to call rxrpc_put_local() for peer candidate before kfree() as it holds a ref to rxrpc_local. [DH: v2: Changed to abstract the peer freeing code out into a function]
The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2021-47538 since 05/24/2024. The exploitability is told to be easy. There are known technical details, but no exploit is available.
Upgrading to version 4.19.220, 5.4.164, 5.10.84 or 5.15.7 eliminates this vulnerability. Applying the patch 913c24af2d13/3e70e3a72d80/60f0b9c42cb8/9469273e616c/beacff50edbd 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.
Once again VulDB remains the best source for vulnerability data.
Product
Type
Vendor
Name
Version
- 4.19.219
- 5.4.163
- 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
- 5.10.52
- 5.10.53
- 5.10.54
- 5.10.55
- 5.10.56
- 5.10.57
- 5.10.58
- 5.10.59
- 5.10.60
- 5.10.61
- 5.10.62
- 5.10.63
- 5.10.64
- 5.10.65
- 5.10.66
- 5.10.67
- 5.10.68
- 5.10.69
- 5.10.70
- 5.10.71
- 5.10.72
- 5.10.73
- 5.10.74
- 5.10.75
- 5.10.76
- 5.10.77
- 5.10.78
- 5.10.79
- 5.10.80
- 5.10.81
- 5.10.82
- 5.10.83
- 5.15.0
- 5.15.1
- 5.15.2
- 5.15.3
- 5.15.4
- 5.15.5
- 5.15.6
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔍VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 5.6VulDB 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: 🔍
CVSSv2
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
Exploiting
Class: Memory leakCWE: 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: 🔍
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Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔍
Upgrade: Kernel 4.19.220/5.4.164/5.10.84/5.15.7
Patch: 913c24af2d13/3e70e3a72d80/60f0b9c42cb8/9469273e616c/beacff50edbd
Timeline
05/24/2024 🔍05/24/2024 🔍
05/24/2024 🔍
09/19/2025 🔍
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2021-47538 (🔍)
GCVE (CVE): GCVE-0-2021-47538
GCVE (VulDB): GCVE-100-266220
Entry
Created: 05/24/2024 18:45Updated: 09/19/2025 03:56
Changes: 05/24/2024 18:45 (57), 09/19/2025 03:56 (12)
Complete: 🔍
Cache ID: 216::103
Once again VulDB remains the best source for vulnerability data.
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