INK Finance lost $140k due to whitelist bypass vulnerability

Article: Muriuki Lazaro, AMB Crypto

INK Finance is a treasury management and workspace infrastructure protocol deployed on Polygon, focused on DeFi, that recently suffered a serious authorization vulnerability attack.

The attacker exploited a weakness in the platform’s treasury verification logic, ultimately transferring about $140k.

The key to this attack was that a forged claimer contract successfully impersonated an approved whitelisted entity within the treasury system.

Due to this bypass, the attacker was able to pass the eligibility check and trigger an “authorized” treasury transfer without immediate restrictions.

Meanwhile, the attacker also accelerated the exploitation by using a roughly $25k Balancer V2 flash loan routed through Railgun to Polygon.

This fund flow also highlights that as DeFi infrastructure becomes more interconnected, the linkage between liquidity systems is increasing attack execution efficiency.

The report pointed out that the attacker did not target high-level encryption layers but exploited operational trust issues surrounding whitelist permissions, further reinforcing external concerns about weak authorization design in treasury architecture.

Treasury authorization systems are becoming a weak link in DeFi

This treasury vulnerability incident reflects a broader shift in DeFi attack surfaces: as infrastructure complexity increases, attackers are no longer focusing solely on liquidity pools or pricing systems but are increasingly targeting high-permission treasury authorization layers that control protocol reserve funds.

INK Finance’s incident also shows that attackers are launching low-cost, high-precision attacks against treasury authorization systems.

This trend indicates that modern attack methods are increasingly emphasizing privilege escalation rather than just broader liquidity manipulation.

Meanwhile, similar whitelist and access control incidents continue to rise in DAO treasury systems in 2026, repeatedly exposing operational verification weaknesses during DeFi infrastructure expansion.

However, these persistent authorization flaws also suggest that decentralized finance still lags behind in operational security maturity relative to its infrastructure and capital scale growth.

Small-scale attacks are also eroding DeFi confidence

An increasing number of attacks targeting treasury authorization are gradually undermining overall market confidence in DeFi infrastructure.

Although INK Finance’s loss was not particularly large, the incident quickly appeared on security dashboards and on-chain monitoring systems.

This visibility is important because users often interpret recurring small security incidents as signals that the underlying infrastructure of the ecosystem remains fragile.

The report also mentioned that similar incidents involving SmartCredit, Sharwa, and Quant continue to reinforce external concerns about weak operational security discipline.

This incident demonstrates that even with limited direct economic loss, small-scale attacks can have disproportionate market impacts, as ongoing authorization failures gradually weaken user confidence, slow capital deployment, and increase systemic risk awareness across interconnected systems.

However, many of these vulnerabilities still stem from avoidable permission configuration issues rather than highly complex technical failures.

In simple terms, operational security maturity still lags behind the development of infrastructure complexity.

Brief Summary

INK Finance lost about $140k after attackers forged a claimer contract to bypass whitelist verification.

Recurring small-scale authorization attacks in DeFi continue to erode user trust in the industry’s infrastructure.