WordPress Otter Blocks Plugin Purchase Verification Bypass

The Otter Blocks plugin for WordPress is vulnerable to Purchase Verification Bypass in all versions up to, and including, 3.1.4. This is due to the 'get_customer_data' method relying on an unsigned 'o_stripe_data' cookie to determine Stripe product ownership for unauthenticated users. The 'check_purchase' method trusts this cookie data without performing server-side verification against the Stripe API for one-time 'payment' mode purchases. This makes it possible for unauthenticated attackers to bypass Stripe purchase-gated content visibility conditions by forging the 'o_stripe_data' cookie with a target product ID, which is publicly exposed in the checkout block's HTML source.

Casky was already ahead

This CVE exploits attack patterns that Casky's 261matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The Otter Blocks WordPress plugin contains a critical authentication flaw where the 'check_purchase' method relies on an unsigned, client-side 'o_stripe_data' cookie to verify Stripe product purchases for unauthenticated users. Rather than validating purchase claims against the actual Stripe API, the plugin trusts cookie data at face value, allowing attackers to forge or modify cookies to bypass payment verification. This affects all versions up to 3.1.4 and impacts any WordPress site using Otter Blocks to gate access to digital products or services behind payment requirements. Attackers can gain unauthorized access to paid content without completing legitimate transactions, directly undermining revenue models and potentially exposing proprietary or restricted materials.

Casky.ai's 261 matched skills detect the attack patterns mapped to TA0004 (Privilege Escalation) and TA0006 (Credential Access) by identifying suspicious authentication bypass behaviors. Practitioners using Casky would observe findings highlighting: (1) client-side trust decisions without server-side validation (CWE-285 - Improper Authorization), (2) cookie manipulation attempts that grant access to restricted resources, and (3) anomalous purchase verification requests lacking cryptographic signature validation. Claude's extended reasoning enables Casky to correlate cookie tampering patterns with unauthorized content access, distinguishing legitimate traffic from attackers forging payment proof—surfacing the core vulnerability that security teams must remediate by implementing mandatory server-side Stripe API verification before granting access to any paid digital assets.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

261 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-2892.

analyzing-cloud-storage-access-patterns

cloud security · low

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analyzing-kubernetes-audit-logs

container security · low

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analyzing-malicious-url-with-urlscan

phishing defense · medium

Run

MITRE ATT&CK Techniques

TA0004 TA0006

Investigate the attack patterns behind CVE-2026-2892

Casky has 261 skills that investigate the attack patterns behind CVE-2026-2892. Run one and get CVSS-scored findings in 3 minutes.

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