CVE-2021-33106

Privilege escalation via incorrect wide-character writes

Published Nov 17, 2021 · Updated Aug 3, 2024

Integer overflow in Intel SafeString Library before commit efbd4066 allows local users to escalate privileges. The wmemset_s function always calls mem_prim_set32 even when wchar_t is 16 bits, writing four-byte values into two-byte elements. Exploitation requires low-privileged local access, high complexity, and user interaction; the crossed privilege boundary is undisclosed.

CVSS severity6.7
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Intel SafeString Library before commit efbd4066 allows local users to escalate privileges. The wmemset_s function always calls mem_prim_set32 even when wchar_t is 16 bits, writing four-byte values into two-byte elements. Exploitation requires low-privileged local access, high complexity, and user interaction; the crossed privilege boundary is undisclosed.

The record

CVE
CVE-2021-33106
Published
Nov 17, 2021
Updated
Aug 3, 2024
Vendor
Intel
Product
SafeString Library
Classifications
CWE-190, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 17, 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?

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  1. Affected versionversion=See references

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Intel · SafeString Libraryversion=See references

Published CVSS scores

6.7IntelCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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