CVE-2022-0240

Process crash via unchecked null class pointer

Published Jan 17, 2022 · Updated Aug 2, 2024

NULL pointer dereference in mruby before 3.2 allows local users to crash an interpreter or embedding application via crafted Ruby code. The mrb_singleton_class_ptr function passes an object with a null class pointer to prepare_singleton_class, which dereferences obj->c without checking it. Exploitation requires execution of attacker-controlled Ruby code in the affected runtime and interrupts only that hosting process.

CVSS severity7.5
High
EPSS probability0.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL pointer dereference in mruby before 3.2 allows local users to crash an interpreter or embedding application via crafted Ruby code. The mrb_singleton_class_ptr function passes an object with a null class pointer to prepare_singleton_class, which dereferences obj->c without checking it. Exploitation requires execution of attacker-controlled Ruby code in the affected runtime and interrupts only that hosting process.

The record

CVE
CVE-2022-0240
Published
Jan 17, 2022
Updated
Aug 2, 2024
Vendor
mruby
Product
mruby
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 17, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <3.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

mruby · mrubyversion=unspecified <3.2

Published CVSS scores

6.2huntr.devCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo