Linux Kernel up to 5.13.3 ibmasm_init_remote_input_dev use after free

CVSS Meta Temp Score
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CTI Interest Score
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6.5$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 5.13.3 and classified as problematic. The impacted element is the function ibmasm_init_remote_input_dev. The manipulation leads to use after free. This vulnerability is referenced as CVE-2021-47334. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.13.3 and classified as problematic. This issue affects the function ibmasm_init_remote_input_dev. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: misc/libmasm/module: Fix two use after free in ibmasm_init_one In ibmasm_init_one, it calls ibmasm_init_remote_input_dev(). Inside ibmasm_init_remote_input_dev, mouse_dev and keybd_dev are allocated by input_allocate_device(), and assigned to sp->remote.mouse_dev and sp->remote.keybd_dev respectively. In the err_free_devices error branch of ibmasm_init_one, mouse_dev and keybd_dev are freed by input_free_device(), and return error. Then the execution runs into error_send_message error branch of ibmasm_init_one, where ibmasm_free_remote_input_dev(sp) is called to unregister the freed sp->remote.mouse_dev and sp->remote.keybd_dev. My patch add a "error_init_remote" label to handle the error of ibmasm_init_remote_input_dev(), to avoid the uaf bugs.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2021-47334. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/26/2024).

The vulnerability scanner Nessus provides a plugin with the ID 209785 (EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)), 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 1512e7dc5eb0/29ba8e2ba89e/5b06ca113bf1/481a76d4749e/38660031e80e/b9c87ce3bc63/ef1067d2baa8/a7268e8a227d/7272b591c4cb 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 (209785). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
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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Nessus ID: 209785
Nessus Name: EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)

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: 1512e7dc5eb0/29ba8e2ba89e/5b06ca113bf1/481a76d4749e/38660031e80e/b9c87ce3bc63/ef1067d2baa8/a7268e8a227d/7272b591c4cb

Timelineinfo

05/21/2024 🔍
05/21/2024 +0 days 🔍
12/26/2024 +219 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47334 (🔍)
GCVE (CVE): GCVE-0-2021-47334
GCVE (VulDB): GCVE-100-265415

Entryinfo

Created: 05/21/2024 17:26
Updated: 12/26/2024 20:51
Changes: 05/21/2024 17:26 (56), 10/29/2024 06:52 (3), 12/26/2024 20:51 (12)
Complete: 🔍
Cache ID: 216::103

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