Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the native marketplace function core/kapp/market/market.go Buy does not check IsClaimed before accepting a bid. A seller can use the Claim seller-accept branch to settle a resting-bid auction while leaving the claimed order loadable with a future EndTime and stale CurrentBid and CurrentBidder values.
A later bidder can submit a higher bid, be debited, and cause the previous bidder to receive a refund even though the NFT has already been delivered. Because Claim and CancelOrder reject the later bidder when IsClaimed is true, the later bidder cannot obtain the NFT or recover the funds. This issue is fixed in version 1.7.20.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/klever-io/klever-go/commit/063bb3ed98f9a84a4b1f7286680613a5f…
security-advisories@github.com
https://github.com/klever-io/klever-go/pull/16
security-advisories@github.com
https://github.com/klever-io/klever-go/releases/tag/v1.7.20
security-advisories@github.com
https://github.com/klever-io/klever-go/security/advisories/GHSA-26r5-4mm2-px5c
security-advisories@github.com