Decoder crash via invalid iterator decrement
Published Apr 21, 2021 · Updated Aug 4, 2024
Out-of-bounds access in Avast RetDec 3.3 allows attackers to crash the bin2llvmir decoder by supplying a crafted PE file. canSplitFunctionOn() in ir_modifications.cpp decrements the result of fncStarts.upper_bound() without checking for begin(), creating an invalid iterator when no earlier function start exists. Processing an attacker-controlled executable is required; the public artifact demonstrates only a crash, while the CVE record lists memory disclosure and code execution without public demonstrations.
Summary
What happened
Out-of-bounds access in Avast RetDec 3.3 allows attackers to crash the bin2llvmir decoder by supplying a crafted PE file. canSplitFunctionOn() in ir_modifications.cpp decrements the result of fncStarts.upper_bound() without checking for begin(), creating an invalid iterator when no earlier function start exists. Processing an attacker-controlled executable is required; the public artifact demonstrates only a crash, while the CVE record lists memory disclosure and code execution without public demonstrations.
The record
- CVE
- CVE-2020-23907
- Published
- Apr 21, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 21, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 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.
Public exploit references
- Issue 637 crafted PE reproducerfunctional · demonstrated
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Technologies
Your stack
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Your stack
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