ZIP-Based SSRF Bypass in HTML-to-PDF Conversion Service

A server-side request forgery (SSRF) vulnerability exists in the Foxit official website’s HTML-to-PDF conversion service. Support for ZIP-formatted input can bypass restrictions on requests to internal IP addresses, potentially allowing discovery of internal network resources.

Casky was already ahead

This CVE exploits attack patterns that Casky's 331matched 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

This vulnerability represents a critical blind spot in input validation where Foxit's HTML-to-PDF conversion service fails to properly sanitize ZIP-formatted requests. Server-side request forgery (SSRF) vulnerabilities are particularly dangerous because they allow attackers to abuse the trusted position of an application server to access internal resources, scan private IP ranges, and potentially reach backend systems that should be isolated from external access. Organizations using Foxit's conversion service—particularly those processing untrusted user-supplied documents—face risks of internal network reconnaissance, credential theft from internal services, and lateral movement into protected infrastructure.

Casky's 331 mapped skills enable Claude AI to correlate SSRF attack patterns across the kill chain: Initial Access (TA0001) techniques involving malicious file uploads, and Command & Control (TA0006) reconnaissance activities where attackers probe internal networks. Practitioners using Casky would observe detection patterns flagging suspicious conversion requests with ZIP-formatted payloads targeting internal IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), unusual DNS resolution patterns for internal hostnames during conversion processing, and HTTP responses leaking internal service information (banner grabbing). The platform's extended reasoning capabilities connect seemingly isolated conversion service logs to broader reconnaissance behavior, surfacing the adversary's systematic mapping of internal resources—a telltale sign of post-compromise lateral movement or supply chain attack preparation.

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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 →

331 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-111418.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0006

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