CVE-2023-30328Public exploit

Local privilege escalation via PID reuse

Published May 4, 2023 · Updated Jan 29, 2025

Privilege escalation in Mailbutler Shimo VPN Client 5.0.4 for macOS allows local users to create arbitrary files as root. The com.feingeist.shimo.helper XPC listener validates a connecting client's processIdentifier rather than its audit token, enabling PID reuse to impersonate a signed Shimo process. A local race winner can invoke writeConfig:atPath:withReply: without Shimo credentials and place attacker-controlled content in root-owned locations.

CVSS severity9.8
Critical
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Mailbutler Shimo VPN Client 5.0.4 for macOS allows local users to create arbitrary files as root. The com.feingeist.shimo.helper XPC listener validates a connecting client's processIdentifier rather than its audit token, enabling PID reuse to impersonate a signed Shimo process. A local race winner can invoke writeConfig:atPath:withReply: without Shimo credentials and place attacker-controlled content in root-owned locations.

The record

CVE
CVE-2023-30328
Published
May 4, 2023
Updated
Jan 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-287, T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1068Exploitation for Privilege Escalation

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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