CVE-2021-47436: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-6xwm-63wf-q2q3
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CVSS 5.5
CWE-476
Published
Advisory Summary

CVE-2021-47436 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (CWE-476: NULL Pointer Dereference) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product dereferences a pointer that it expects to be valid but is null.. Remediation is available in the latest vendor maintenance releases.

CVE-2021-47436 at a Glance

CVE Identifier CVE-2021-47436
GHSA Identifier GHSA-6xwm-63wf-q2q3
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-476: NULL Pointer Dereference
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-47436

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-47436, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-476: NULL Pointer Dereference, where the product dereferences a pointer that it expects to be valid but is null. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In the Linux kernel, the following vulnerability has been resolved: usb: musb: dsps: Fix the probe error path Commit 7c75bde329d7 ("usb: musb: musb_dsps: request_irq() after initializing musb") has inverted the calls to dsps_setup_optional_vbus_irq() and dsps_create_musb_pdev() without updating correctly the error path. dsps_create_musb_pdev() allocates and registers a new platform device which must be unregistered and freed with platform_device_unregister(), and this is missing upon dsps_setup_optional_vbus_irq() error. While on the master branch it seems not to trigger any issue, I observed a kernel crash because of a NULL pointer dereference with a v5.10.70 stable kernel where the patch mentioned above was backported. With this kernel version, -EPROBE_DEFER is returned the first time dsps_setup_optional_vbus_irq() is called which triggers the probe to error out without unregistering the platform device. Unfortunately, on the Beagle Bone Black Wireless, the platform device still living in the system is being used by the USB Ethernet gadget driver, which during the boot phase triggers the crash. My limited knowledge of the musb world prevents me to revert this commit which was sent to silence a robot warning which, as far as I understand, does not make sense. The goal of this patch was to prevent an IRQ to fire before the platform device being registered. I think this cannot ever happen due to the fact that enabling the interrupts is done by the ->enable() callback of the platform musb device, and this platform device must be already registered in order for the core or any other user to use this callback. Hence, I decided to fix the error path, which might prevent future errors on mainline kernels while also fixing older ones.

References

NVD — CVE-2021-47436 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-47436
git.kernel.org/stable/c/5ed60a430f... WEB
https://git.kernel.org/stable/c/5ed60a430fb5f3d93e7fef66264daef466b4d10c
git.kernel.org/stable/c/9ab5d539bc... WEB
https://git.kernel.org/stable/c/9ab5d539bc975b8dcde86eca1b58d836b657732e
git.kernel.org/stable/c/9d89e28711... WEB
https://git.kernel.org/stable/c/9d89e287116796bf987cc48f5c8632ef3048f8eb
git.kernel.org/stable/c/c2115b2b16... WEB
https://git.kernel.org/stable/c/c2115b2b16421d93d4993f3fe4c520e91d6fe801
git.kernel.org/stable/c/e923bce31f... WEB
https://git.kernel.org/stable/c/e923bce31ffefe4f60edfc6b84f62d4a858f3676
git.kernel.org/stable/c/ff9249aab3... WEB
https://git.kernel.org/stable/c/ff9249aab39820be11b6975a10d94253b7d426fc

Frequently Asked Questions

What is CVE-2021-47436?
CVE-2021-47436 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-476: NULL Pointer Dereference.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-47436?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2021-47436?
CVE-2021-47436 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-47436?
CVE-2021-47436 is classified under CWE-476: NULL Pointer Dereference (The product dereferences a pointer that it expects to be valid but is NULL.).
How can I check Maven dependencies for CVE-2021-47436?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6xwm-63wf-q2q3",
  "modified" : "2025-03-01T03:30:51Z",
  "published" : "2024-05-22T09:31:44Z",
  "aliases" : [ "CVE-2021-47436" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: musb: dsps: Fix the probe error path\n\nCommit 7c75bde329d7 (\"usb: musb: musb_dsps: request_irq() after\ninitializing musb\") has inverted the calls to\ndsps_setup_optional_vbus_irq() and dsps_create_musb_pdev() without\nupdating correctly the error path. dsps_create_musb_pdev() allocates and\nregisters a new platform device which must be unregistered and freed\nwith platform_device_unregister(), and this is missing upon\ndsps_setup_optional_vbus_irq() error.\n\nWhile on the master branch it seems not to trigger any issue, I observed\na kernel crash because of a NULL pointer dereference with a v5.10.70\nstable kernel where the patch mentioned above was backported. With this\nkernel version, -EPROBE_DEFER is returned the first time\ndsps_setup_optional_vbus_irq() is called which triggers the probe to\nerror out without unregistering the platform device. Unfortunately, on\nthe Beagle Bone Black Wireless, the platform device still living in the\nsystem is being used by the USB Ethernet gadget driver, which during the\nboot phase triggers the crash.\n\nMy limited knowledge of the musb world prevents me to revert this commit\nwhich was sent to silence a robot warning which, as far as I understand,\ndoes not make sense. The goal of this patch was to prevent an IRQ to\nfire before the platform device being registered. I think this cannot\never happen due to the fact that enabling the interrupts is done by the\n->enable() callback of the platform musb device, and this platform\ndevice must be already registered in order for the core or any other\nuser to use this callback.\n\nHence, I decided to fix the error path, which might prevent future\nerrors on mainline kernels while also fixing older ones.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-47436"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/5ed60a430fb5f3d93e7fef66264daef466b4d10c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9ab5d539bc975b8dcde86eca1b58d836b657732e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9d89e287116796bf987cc48f5c8632ef3048f8eb"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c2115b2b16421d93d4993f3fe4c520e91d6fe801"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e923bce31ffefe4f60edfc6b84f62d4a858f3676"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ff9249aab39820be11b6975a10d94253b7d426fc"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-476" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2024-05-22T07:15:08Z"
  }
}