Memory disclosure via unchecked GSUB glyph count
Published Jun 2, 2025 · Updated Jun 2, 2025
Out-of-bounds read in the GSUB parser in High-Logic FontCreator 15.0.0.3015 allows attackers to disclose memory via a crafted font file. The GSUB CoverageFormat2 parser derives totalGlyphId from attacker-controlled range records, then uses that count to index the shorter substitutes array without a matching bounds check. A user must open the file; the documented effects are adjacent process-memory disclosure and an access-violation crash, with no integrity impact.
Summary
What happened
Out-of-bounds read in the GSUB parser in High-Logic FontCreator 15.0.0.3015 allows attackers to disclose memory via a crafted font file. The GSUB CoverageFormat2 parser derives totalGlyphId from attacker-controlled range records, then uses that count to index the shorter substitutes array without a matching bounds check. A user must open the file; the documented effects are adjacent process-memory disclosure and an access-violation crash, with no integrity impact.
The record
- CVE
- CVE-2025-20001
- Published
- Jun 2, 2025
- Updated
- Jun 2, 2025
- Vendor
- High-Logic
- Product
- FontCreator
- Classifications
- CWE-125, T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 2, 2025CVE publishedPublication date reported by the CVE source.
- Jun 2, 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?
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- Affected versionversion=15.0.0.3015
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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