CVE-2023-27953Network attack vector

Process-memory disclosure via uninitialized DCERPC reply array

Published May 8, 2023 · Updated Nov 4, 2025

Uninitialized-memory disclosure in Apple macOS before 11.7.5, 12.6.4, or 13.3 allows remote authenticated users to read process memory. DCERPC reply marshalling passes an allocated but uninitialized mdssvc output array to strlen, then copies residual heap contents into the RPC reply. The remote path requires SMB authentication and a request for a nonexistent share; a local user can reach the same mdssvc endpoint through its Unix socket.

CVSS severity9.8
Critical
EPSS probability1.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-memory disclosure in Apple macOS before 11.7.5, 12.6.4, or 13.3 allows remote authenticated users to read process memory. DCERPC reply marshalling passes an allocated but uninitialized mdssvc output array to strlen, then copies residual heap contents into the RPC reply. The remote path requires SMB authentication and a request for a nonexistent share; a local user can reach the same mdssvc endpoint through its Unix socket.

The record

CVE
CVE-2023-27953
Published
May 8, 2023
Updated
Nov 4, 2025
Vendor
Apple
Product
macOS
Classifications
CWE-457, CWE-787, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record 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 <11.7
  2. Affected versionversion=unspecified <12.6
  3. Affected versionversion=unspecified <13.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Apple · macOSversion=unspecified <11.7; version=unspecified <12.6; version=unspecified <13.3

Published CVSS scores

5.3Cisco TalosCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-457Use of Uninitialized Variable
CWE-787Out-of-bounds Write
T1210Exploitation of Remote Services

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

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Your stack

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