Financial loss via unchecked recipient-balance addition
Published Aug 3, 2021 · Updated Aug 3, 2024
Integer overflow in Lancer Token allows remote authenticated users to reduce account balances through a crafted token transfer. The transfer function adds the supplied value to balances[_to] without checking whether the uint256 sum exceeds 2^256, so the recipient balance wraps to a smaller number. Exploitation requires contract-owner access and two sufficiently large balances; the resulting balance corruption causes direct financial loss.
Summary
What happened
Integer overflow in Lancer Token allows remote authenticated users to reduce account balances through a crafted token transfer. The transfer function adds the supplied value to balances[_to] without checking whether the uint256 sum exceeds 2^256, so the recipient balance wraps to a smaller number. Exploitation requires contract-owner access and two sufficiently large balances; the resulting balance corruption causes direct financial loss.
The record
- CVE
- CVE-2021-33403
- Published
- Aug 3, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190, T1657
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Aug 3, 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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Is a vulnerable build present?
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
- SC-RCVD LNCToken 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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