Application crash via out-of-bounds parser read
Published Apr 29, 2021 · Updated Aug 3, 2024
Use of uninitialized memory in md4c 0.4.7 allows attackers to crash applications that parse a malformed Markdown document. md_analyze_line reads the byte at off after off reaches ctx->size while classifying complex lines, consuming one byte beyond the supplied input. The application must pass attacker-controlled Markdown to the library; the published reproducer triggers the invalid read through md2html under MemorySanitizer.
Summary
What happened
Use of uninitialized memory in md4c 0.4.7 allows attackers to crash applications that parse a malformed Markdown document. md_analyze_line reads the byte at off after off reaches ctx->size while classifying complex lines, consuming one byte beyond the supplied input. The application must pass attacker-controlled Markdown to the library; the published reproducer triggers the invalid read through md2html under MemorySanitizer.
The record
- CVE
- CVE-2021-30027
- Published
- Apr 29, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-908
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 29, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Issue 155 MemorySanitizer reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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