CVE-2025-21731: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-2qfv-5w3v-jvfv
CVSS 7.8
CWE-416
Published
Advisory Summary

CVE-2025-21731 is a HIGH (CVSS 7.8) security vulnerability vulnerability (CWE-416: Use After Free) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.. Remediation is available in the latest vendor maintenance releases.

CVE-2025-21731 at a Glance

CVE Identifier CVE-2025-21731
GHSA Identifier GHSA-2qfv-5w3v-jvfv
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-416: Use After Free
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-21731

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-2025-21731, 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-416: Use After Free, where the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. 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: nbd: don't allow reconnect after disconnect Following process can cause nbd_config UAF: 1) grab nbd_config temporarily; 2) nbd_genl_disconnect() flush all recv_work() and release the initial reference: nbd_genl_disconnect nbd_disconnect_and_put nbd_disconnect flush_workqueue(nbd->recv_workq) if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...)) nbd_config_put -> due to step 1), reference is still not zero 3) nbd_genl_reconfigure() queue recv_work() again; nbd_genl_reconfigure config = nbd_get_config_unlocked(nbd) if (!config) -> succeed if (!test_bit(NBD_RT_BOUND, ...)) -> succeed nbd_reconnect_socket queue_work(nbd->recv_workq, &args->work) 4) step 1) release the reference; 5) Finially, recv_work() will trigger UAF: recv_work nbd_config_put(nbd) -> nbd_config is freed atomic_dec(&config->recv_threads) -> UAF Fix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so that nbd_genl_reconfigure() will fail.

References

NVD — CVE-2025-21731 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-21731
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-457936.html
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-784472.html
git.kernel.org/stable/c/6bef6222a3... WEB
https://git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a
git.kernel.org/stable/c/844b8cdc68... WEB
https://git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1
git.kernel.org/stable/c/9793bd5ae4... WEB
https://git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302
git.kernel.org/stable/c/a8ee6ecde2... WEB
https://git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739
git.kernel.org/stable/c/d208d2c52b... WEB
https://git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f
git.kernel.org/stable/c/e3be8862d7... WEB
https://git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11
git.kernel.org/stable/c/e70a578487... WEB
https://git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381
git.kernel.org/stable/c/e7343fa337... WEB
https://git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html

Frequently Asked Questions

What is CVE-2025-21731?
CVE-2025-21731 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-416: Use After Free.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2025-21731?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2025-21731?
CVE-2025-21731 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-21731?
CVE-2025-21731 is classified under CWE-416: Use After Free (The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.).
How can I check Maven dependencies for CVE-2025-21731?
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
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  "id" : "GHSA-2qfv-5w3v-jvfv",
  "modified" : "2026-10-15T03:34:32Z",
  "published" : "2025-02-27T03:34:02Z",
  "aliases" : [ "CVE-2025-21731" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: don't allow reconnect after disconnect\n\nFollowing process can cause nbd_config UAF:\n\n1) grab nbd_config temporarily;\n\n2) nbd_genl_disconnect() flush all recv_work() and release the\ninitial reference:\n\n  nbd_genl_disconnect\n   nbd_disconnect_and_put\n    nbd_disconnect\n     flush_workqueue(nbd->recv_workq)\n    if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...))\n     nbd_config_put\n     -> due to step 1), reference is still not zero\n\n3) nbd_genl_reconfigure() queue recv_work() again;\n\n  nbd_genl_reconfigure\n   config = nbd_get_config_unlocked(nbd)\n   if (!config)\n   -> succeed\n   if (!test_bit(NBD_RT_BOUND, ...))\n   -> succeed\n   nbd_reconnect_socket\n    queue_work(nbd->recv_workq, &args->work)\n\n4) step 1) release the reference;\n\n5) Finially, recv_work() will trigger UAF:\n\n  recv_work\n   nbd_config_put(nbd)\n   -> nbd_config is freed\n   atomic_dec(&config->recv_threads)\n   -> UAF\n\nFix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so\nthat nbd_genl_reconfigure() will fail.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
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    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302"
  }, {
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    "url" : "https://git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381"
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    "url" : "https://git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"
  } ],
  "database_specific" : {
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    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2025-02-27T02:15:16Z"
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}