CVE-2021-47488: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-xvmj-27r5-9623
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Advisory Summary

CVE-2021-47488 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2021-47488 at a Glance

CVE Identifier CVE-2021-47488
GHSA Identifier GHSA-xvmj-27r5-9623
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2021-47488

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-2021-47488, 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 General Security Weakness. 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: cgroup: Fix memory leak caused by missing cgroup_bpf_offline When enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running the command as below: $mount -t cgroup -o none,name=foo cgroup cgroup/ $umount cgroup/ unreferenced object 0xc3585c40 (size 64): comm "mount", pid 425, jiffies 4294959825 (age 31.990s) hex dump (first 32 bytes): 01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00 ......(......... 00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00 ........lC...... backtrace: [<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c [<1f03679c>] cgroup_setup_root+0x174/0x37c [<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0 [<f85b12fd>] vfs_get_tree+0x24/0x108 [<f55aec5c>] path_mount+0x384/0x988 [<e2d5e9cd>] do_mount+0x64/0x9c [<208c9cfe>] sys_mount+0xfc/0x1f4 [<06dd06e0>] ret_fast_syscall+0x0/0x48 [<a8308cb3>] 0xbeb4daa8 This is because that since the commit 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path") root_cgrp->bpf.refcnt.data is allocated by the function percpu_ref_init in cgroup_bpf_inherit which is called by cgroup_setup_root when mounting, but not freed along with root_cgrp when umounting. Adding cgroup_bpf_offline which calls percpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in umount path. This patch also fixes the commit 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself"). A cgroup_bpf_offline is needed to do a cleanup that frees the resources which are allocated by cgroup_bpf_inherit in cgroup_setup_root. And inside cgroup_bpf_offline, cgroup_get() is at the beginning and cgroup_put is at the end of cgroup_bpf_release which is called by cgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of cgroup's refcount.

References

NVD — CVE-2021-47488 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-47488
git.kernel.org/stable/c/01599bf7cc... WEB
https://git.kernel.org/stable/c/01599bf7cc2b49c3d2be886cb438647dc25446ed
git.kernel.org/stable/c/04f8ef5643... WEB
https://git.kernel.org/stable/c/04f8ef5643bcd8bcde25dfdebef998aea480b2ba
git.kernel.org/stable/c/b529f88d93... WEB
https://git.kernel.org/stable/c/b529f88d93884cf8ccafda793ee3d27b82fa578d

Frequently Asked Questions

What is CVE-2021-47488?
CVE-2021-47488 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-47488?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2021-47488?
CVE-2021-47488 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2021-47488?
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-xvmj-27r5-9623",
  "modified" : "2024-05-22T09:31:46Z",
  "published" : "2024-05-22T09:31:46Z",
  "aliases" : [ "CVE-2021-47488" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup: Fix memory leak caused by missing cgroup_bpf_offline\n\nWhen enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running\nthe command as below:\n\n    $mount -t cgroup -o none,name=foo cgroup cgroup/\n    $umount cgroup/\n\nunreferenced object 0xc3585c40 (size 64):\n  comm \"mount\", pid 425, jiffies 4294959825 (age 31.990s)\n  hex dump (first 32 bytes):\n    01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00  ......(.........\n    00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00  ........lC......\n  backtrace:\n    [<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c\n    [<1f03679c>] cgroup_setup_root+0x174/0x37c\n    [<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0\n    [<f85b12fd>] vfs_get_tree+0x24/0x108\n    [<f55aec5c>] path_mount+0x384/0x988\n    [<e2d5e9cd>] do_mount+0x64/0x9c\n    [<208c9cfe>] sys_mount+0xfc/0x1f4\n    [<06dd06e0>] ret_fast_syscall+0x0/0x48\n    [<a8308cb3>] 0xbeb4daa8\n\nThis is because that since the commit 2b0d3d3e4fcf (\"percpu_ref: reduce\nmemory footprint of percpu_ref in fast path\") root_cgrp->bpf.refcnt.data\nis allocated by the function percpu_ref_init in cgroup_bpf_inherit which\nis called by cgroup_setup_root when mounting, but not freed along with\nroot_cgrp when umounting. Adding cgroup_bpf_offline which calls\npercpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in\numount path.\n\nThis patch also fixes the commit 4bfc0bb2c60e (\"bpf: decouple the lifetime\nof cgroup_bpf from cgroup itself\"). A cgroup_bpf_offline is needed to do a\ncleanup that frees the resources which are allocated by cgroup_bpf_inherit\nin cgroup_setup_root.\n\nAnd inside cgroup_bpf_offline, cgroup_get() is at the beginning and\ncgroup_put is at the end of cgroup_bpf_release which is called by\ncgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of\ncgroup's refcount.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-47488"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/01599bf7cc2b49c3d2be886cb438647dc25446ed"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/04f8ef5643bcd8bcde25dfdebef998aea480b2ba"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b529f88d93884cf8ccafda793ee3d27b82fa578d"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2024-05-22T09:15:10Z"
  }
}