Service interruption via unreleased IMPORTASSETS allocations
Published May 9, 2023 · Updated Jan 29, 2025
A memory leak in libming 0.4.8 allows local users to exhaust process memory by parsing a crafted SWF IMPORTASSETS block. parseSWF_IMPORTASSETS in util/parser.c allocates an import URL and symbol strings but leaves them and later unknown-block buffers unreleased when malformed input desynchronizes the stream. The published reproducer reports 527 bytes leaked across 13 allocations; it demonstrates resource exhaustion, not the arbitrary code execution asserted by the CVE description.
Summary
What happened
A memory leak in libming 0.4.8 allows local users to exhaust process memory by parsing a crafted SWF IMPORTASSETS block. parseSWF_IMPORTASSETS in util/parser.c allocates an import URL and symbol strings but leaves them and later unknown-block buffers unreleased when malformed input desynchronizes the stream. The published reproducer reports 527 bytes leaked across 13 allocations; it demonstrates resource exhaustion, not the arbitrary code execution asserted by the CVE description.
The record
- CVE
- CVE-2021-31240
- Published
- May 9, 2023
- Updated
- Jan 29, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-401, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 9, 2023CVE publishedPublication date reported by the CVE source.
- Jan 29, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
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
- parseSWF_IMPORTASSETS memory-leak reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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