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Vulnerabilities/CVE-2021-3999Public Intelligence Dossier
Source: gnu · Limited verification•Last verified: •Collection Degraded
CVE-2021-3999Unknown / EvaluatingHIGH (raw)CVSS 7.8CWE-193

A flaw was found in glibc

Published: 24 Aug 2022•Last updated: 14 Oct 2026, 03:47 PM IST•Source identifier: secalert@redhat.com
Dossier completeness: source-provided sections 2 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
7.8HIGH (raw)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Metric sourcenvd@nist.gov
EPSS probability
0.8%0.008
Percentile56th
Weakness type
CWE-193
No further CWE recorded
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

A flaw was found in glibc. An off-by-one buffer overflow and underflow in getcwd() may lead to memory corruption when the size of the buffer is exactly 1. A local attacker who can control the input buffer and size passed to getcwd() in a setuid program could use this flaw to potentially execute arbitrary code and escalate their privileges on the system.

SOC priority

High

Actively exploited

Unknown

Publicly disclosed

Unknown

Risk basis: SOC ecosystem technology relevance; HIGH severity; No confirmed exploitation signal in current enrichment

Affected Products & Remediation

10 source-backed products
Affected products and versions (source)
  • gnu glibc · < 2.31 · NVD CPE · Source
  • debian debian linux · 10.0; 11.0 · NVD CPE · Source
  • netapp e-series performance analyzer · version range not provided by source · NVD CPE · Source
  • netapp nfs plug-in · version range not provided by source · NVD CPE · Source
  • netapp ontap select deploy administration utility · version range not provided by source · NVD CPE · Source
  • netapp h300s firmware · version range not provided by source · NVD CPE · Source
  • netapp h500s firmware · version range not provided by source · NVD CPE · Source
  • netapp h700s firmware · version range not provided by source · NVD CPE · Source
  • netapp h410s firmware · version range not provided by source · NVD CPE · Source
  • netapp h410c firmware · version range not provided by source · NVD CPE · Source
NVD applicability prerequisites: cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:*. These are conditions, not proof that an environment is exposed or unaffected.
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

Not provided by source

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
Unknown
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched local-privilege-escalation (CVSS AV:L, CVSS PR:L)

Exposure

  1. Identify hosts reporting this CVE, prioritising shared or multi-user systems.Telemetry: DeviceTvmSoftwareVulnerabilities · A local, low-privilege vector matters most where untrusted users can run code. · Rule local-privilege-escalation

Exploitation evidence

  1. Look for low-privileged processes spawning SYSTEM or root-level child processes on affected hosts.Telemetry: DeviceProcessEvents · Hunting hypothesis from the CVSS vector; privilege transitions are a focused starting point, not evidence of attack. · Rule local-privilege-escalation

Response

  1. Confirm the source-stated update on affected hosts.Telemetry: DeviceTvmSoftwareVulnerabilities · Host inventory can verify remediation. · Rule local-privilege-escalation

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
secalert@redhat.com
Record status · verification
UPDATED · NVD API
CPE
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*, cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*, cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*, cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:*, cpe:2.3:a:netapp:nfs_plug-in:*:*:*:*:*:vmware_vaai:*:*, cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*, cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:*, cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*, cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:*

Evidence & Provenance

3 public sources
nvd.nist.govSource recordaccess.redhat.comSource recordbugzilla.redhat.comSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2021-3999
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2021-3999
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2021-3999"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library

Correlated briefings

— No published briefing references this CVE

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.