CVE-2021-46910: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-gg7f-9mpf-7m5f
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CVSS 5.5
Published
Advisory Summary

CVE-2021-46910 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2021-46910 at a Glance

CVE Identifier CVE-2021-46910
GHSA Identifier GHSA-gg7f-9mpf-7m5f
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification General Security Weakness
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-2021-46910

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-2021-46910, 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: ARM: 9063/1: mm: reduce maximum number of CPUs if DEBUG_KMAP_LOCAL is enabled The debugging code for kmap_local() doubles the number of per-CPU fixmap slots allocated for kmap_local(), in order to use half of them as guard regions. This causes the fixmap region to grow downwards beyond the start of its reserved window if the supported number of CPUs is large, and collide with the newly added virtual DT mapping right below it, which is obviously not good. One manifestation of this is EFI boot on a kernel built with NR_CPUS=32 and CONFIG_DEBUG_KMAP_LOCAL=y, which may pass the FDT in highmem, resulting in block entries below the fixmap region that the fixmap code misidentifies as fixmap table entries, and subsequently tries to dereference using a phys-to-virt translation that is only valid for lowmem. This results in a cryptic splat such as the one below. ftrace: allocating 45548 entries in 89 pages 8<--- cut here --- Unable to handle kernel paging request at virtual address fc6006f0 pgd = (ptrval) [fc6006f0] *pgd=80000040207003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0+ #382 Hardware name: Generic DT based system PC is at cpu_ca15_set_pte_ext+0x24/0x30 LR is at __set_fixmap+0xe4/0x118 pc : [<c041ac9c>] lr : [<c04189d8>] psr: 400000d3 sp : c1601ed8 ip : 00400000 fp : 00800000 r10: 0000071f r9 : 00421000 r8 : 00c00000 r7 : 00c00000 r6 : 0000071f r5 : ffade000 r4 : 4040171f r3 : 00c00000 r2 : 4040171f r1 : c041ac78 r0 : fc6006f0 Flags: nZcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 40203000 DAC: 00000001 Process swapper (pid: 0, stack limit = 0x(ptrval)) So let's limit CONFIG_NR_CPUS to 16 when CONFIG_DEBUG_KMAP_LOCAL=y. Also, fix the BUILD_BUG_ON() check that was supposed to catch this, by checking whether the region grows below the start address rather than above the end address.

References

NVD — CVE-2021-46910 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-46910
git.kernel.org/stable/c/5965ac11b1... WEB
https://git.kernel.org/stable/c/5965ac11b1d5fcb38464728931649cd9df79c7c9
git.kernel.org/stable/c/d624833f59... WEB
https://git.kernel.org/stable/c/d624833f5984d484c5e3196f34b926f9e71dafee

Frequently Asked Questions

What is CVE-2021-46910?
CVE-2021-46910 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-2021-46910?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2021-46910?
CVE-2021-46910 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-2021-46910?
CVE-2021-46910 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2021-46910?
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-gg7f-9mpf-7m5f",
  "modified" : "2024-04-17T18:31:31Z",
  "published" : "2024-02-27T09:31:15Z",
  "aliases" : [ "CVE-2021-46910" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nARM: 9063/1: mm: reduce maximum number of CPUs if DEBUG_KMAP_LOCAL is enabled\n\nThe debugging code for kmap_local() doubles the number of per-CPU fixmap\nslots allocated for kmap_local(), in order to use half of them as guard\nregions. This causes the fixmap region to grow downwards beyond the start\nof its reserved window if the supported number of CPUs is large, and collide\nwith the newly added virtual DT mapping right below it, which is obviously\nnot good.\n\nOne manifestation of this is EFI boot on a kernel built with NR_CPUS=32\nand CONFIG_DEBUG_KMAP_LOCAL=y, which may pass the FDT in highmem, resulting\nin block entries below the fixmap region that the fixmap code misidentifies\nas fixmap table entries, and subsequently tries to dereference using a\nphys-to-virt translation that is only valid for lowmem. This results in a\ncryptic splat such as the one below.\n\n  ftrace: allocating 45548 entries in 89 pages\n  8<--- cut here ---\n  Unable to handle kernel paging request at virtual address fc6006f0\n  pgd = (ptrval)\n  [fc6006f0] *pgd=80000040207003, *pmd=00000000\n  Internal error: Oops: a06 [#1] SMP ARM\n  Modules linked in:\n  CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0+ #382\n  Hardware name: Generic DT based system\n  PC is at cpu_ca15_set_pte_ext+0x24/0x30\n  LR is at __set_fixmap+0xe4/0x118\n  pc : [<c041ac9c>]    lr : [<c04189d8>]    psr: 400000d3\n  sp : c1601ed8  ip : 00400000  fp : 00800000\n  r10: 0000071f  r9 : 00421000  r8 : 00c00000\n  r7 : 00c00000  r6 : 0000071f  r5 : ffade000  r4 : 4040171f\n  r3 : 00c00000  r2 : 4040171f  r1 : c041ac78  r0 : fc6006f0\n  Flags: nZcv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment none\n  Control: 30c5387d  Table: 40203000  DAC: 00000001\n  Process swapper (pid: 0, stack limit = 0x(ptrval))\n\nSo let's limit CONFIG_NR_CPUS to 16 when CONFIG_DEBUG_KMAP_LOCAL=y. Also,\nfix the BUILD_BUG_ON() check that was supposed to catch this, by checking\nwhether the region grows below the start address rather than above the end\naddress.",
  "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-2021-46910"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/5965ac11b1d5fcb38464728931649cd9df79c7c9"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d624833f5984d484c5e3196f34b926f9e71dafee"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2024-02-27T07:15:07Z"
  }
}