Heap over-read via malformed UTF-8 traversal
Published Dec 27, 2024 · Updated Dec 28, 2024
Heap-based buffer overflow in HarfBuzz 8.5.0 through 10.0.1 allows attackers to read beyond a heap buffer via malformed UTF-8 text. The hb_cairo_glyphs_from_buffer function assumes valid UTF-8, while hb_utf_offset_to_pointer derives traversal bounds from the current pointer instead of the full text buffer. Reaching the flaw requires attacker-controlled malformed UTF-8 to enter the Cairo glyph-conversion path; the published proof of concept triggers an invalid one-byte read in hb-view.
Summary
What happened
Heap-based buffer overflow in HarfBuzz 8.5.0 through 10.0.1 allows attackers to read beyond a heap buffer via malformed UTF-8 text. The hb_cairo_glyphs_from_buffer function assumes valid UTF-8, while hb_utf_offset_to_pointer derives traversal bounds from the current pointer instead of the full text buffer. Reaching the flaw requires attacker-controlled malformed UTF-8 to enter the Cairo glyph-conversion path; the published proof of concept triggers an invalid one-byte read in hb-view.
The record
- CVE
- CVE-2024-56732
- Published
- Dec 27, 2024
- Updated
- Dec 28, 2024
- Vendor
- HarfBuzz
- Product
- HarfBuzz
- Classifications
- CWE-122, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 27, 2024CVE publishedPublication date reported by the CVE source.
- Dec 28, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 8.5.0, <= 10.0.1
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.
Public exploit references
- HarfBuzz malformed UTF-8 proof of conceptproof of concept · demonstrated
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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