Unpacker crash via unchecked PT_DYNAMIC offsets
Published Jun 1, 2020 · Updated Aug 5, 2024
Integer overflow in UPX before 3.96 allows local users to crash the unpacker by processing a crafted Linux ELF file. The PT_DYNAMIC parser translates attacker-controlled d_val offsets and adds them to file_image without an upper-bound check, allowing out-of-range pointers to reach hash-table dereferences. Exploitation requires a user or local workflow to invoke UPX decompression on the malicious file; the documented consequence is an unpacker crash, not code execution or data disclosure.
Summary
What happened
Integer overflow in UPX before 3.96 allows local users to crash the unpacker by processing a crafted Linux ELF file. The PT_DYNAMIC parser translates attacker-controlled d_val offsets and adds them to file_image without an upper-bound check, allowing out-of-range pointers to reach hash-table dereferences. Exploitation requires a user or local workflow to invoke UPX decompression on the malicious file; the documented consequence is an unpacker crash, not code execution or data disclosure.
The record
- CVE
- CVE-2019-20805
- Published
- Jun 1, 2020
- Updated
- Aug 5, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 1, 2020CVE publishedPublication date reported by the CVE source.
- Aug 5, 2024Record 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.
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
- UPX issue 317 crafted ELF inputsproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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