CVE-2021-3622Public exploitNetwork attack vector

Process crash via unbounded ri-record recursion

Published Dec 23, 2021 · Updated Aug 3, 2024

Stack exhaustion in libguestfs Hivex before 1.3.21 allows attackers to crash linked programs by supplying a crafted Registry hive file. The lib/node.c _get_children function follows arbitrarily deep chains of nested ri records without a recursion limit, exhausting the process stack. Exploitation requires a user or automated workflow to make a Hivex-linked program open and enumerate the malicious hive; only that process crashes.

CVSS severity4.3
Medium
EPSS probability4.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack exhaustion in libguestfs Hivex before 1.3.21 allows attackers to crash linked programs by supplying a crafted Registry hive file. The lib/node.c _get_children function follows arbitrarily deep chains of nested ri records without a recursion limit, exhausting the process stack. Exploitation requires a user or automated workflow to make a Hivex-linked program open and enumerate the malicious hive; only that process crashes.

The record

CVE
CVE-2021-3622
Published
Dec 23, 2021
Updated
Aug 3, 2024
Vendor
libguestfs
Product
Hivex
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=hivex-1.3.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

libguestfs · Hivexversion=hivex-1.3.21

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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