Privilege escalation via unchecked SAPI XML attributes
Published Nov 14, 2023 · Updated Oct 9, 2025
Stack buffer overflow in Microsoft Windows SAPI allows local users to execute code with elevated privileges through crafted speech XML. The custom XML fallback in sapi.dll's ParseTag loop appends more than 10 attributes to a fixed XMLTAG.Attrs array without bounds checking, corrupting the stack. A low-privileged context must invoke ISpVoice::Speak; Chromium's Web Speech JavaScript can reach SAPI outside the renderer sandbox, enabling browser-process compromise.
Summary
What happened
Stack buffer overflow in Microsoft Windows SAPI allows local users to execute code with elevated privileges through crafted speech XML. The custom XML fallback in sapi.dll's ParseTag loop appends more than 10 attributes to a fixed XMLTAG.Attrs array without bounds checking, corrupting the stack. A low-privileged context must invoke ISpVoice::Speak; Chromium's Web Speech JavaScript can reach SAPI outside the renderer sandbox, enabling browser-process compromise.
The record
- CVE
- CVE-2023-36719
- Published
- Nov 14, 2023
- Updated
- Oct 9, 2025
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-20, T1068, T1203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 14, 2023CVE publishedPublication date reported by the CVE source.
- Oct 9, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.10240.0 <10.0.10240.20308
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Microsoft SAPI Web Speech JavaScript proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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