Attack arithmetic: how an integer overflow in PostgreSQL libpq leads to denial of service

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Databases serve as the foundation of the digital world, organizing and storing critical information: from financial transactions and medical records to website content. However, like any complex software product, they are not immune to flaws, and discovered vulnerabilities can turn this repository into a prime target for attacks. This applies in full to PostgreSQL as well—a system with a reputation as a benchmark of reliability, whose hidden issues may be no less serious than its obvious advantages.

PostgreSQL is a free, open source object relational database management system (DBMS). It stores, processes, and retrieves data using SQL, and supports modern features such as user data, stored procedures, and triggers. PostgreSQL is known for its reliability, flexibility, scalability, and ability to work with complex datasets.

libpq is PostgreSQL’s official client library designed for interacting with PostgreSQL databases from programs written in C. It is distributed as part of PostgreSQL and provides a low level API for connecting to a PostgreSQL server, executing SQL queries, processing results, and managing connections.

We identified an integer overflow vulnerability in the PQescapeInternal function, which is called by PQescapeLiteral and PQescapeIdentifier.

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Blind trust: what is hidden behind the process of creating your PDF file?

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Every day, thousands of web services generate PDF (Portable Document Format) files—bills, contracts, reports. This step is often treated as a technical routine, “just convert the HTML,” but in practice it’s exactly where a trust boundary is crossed. The renderer parses HTML, downloads external resources, processes fonts, SVGs, and images, and sometimes has access to the network and the file system. Risky behavior can occur by default, without explicit options or warnings. That is enough for a PDF converter to become an SSRF proxy, a data leak channel, or even cause denial of service.

We therefore conducted a targeted analysis of popular HTML-to-PDF libraries written in the PHP, JavaScript, and Java languages: TCPDF, html2pdf, jsPDF, mPDF, snappy, dompdf, and OpenPDF. During the research, the PT Swarm team identified 13 vulnerabilities, demonstrated 7 intentional behaviors, and highlighted 6 potential misconfigurations. These included vulnerability classes such as Files or Directories Accessible to External Parties, Deserialization of Untrusted Data, Server-Side Request Forgery, and Denial of Service.

PDF generation is increasingly common across e‑commerce, fintech, logistics, and SaaS. Such services are often deployed inside the perimeter, next to sensitive data, where network controls are looser. This means that even a seemingly harmless bug in the renderer can escalate into a serious incident: leakage of documents, secrets, or internal URLs.

In this article, we present a threat model for an HTML-to-PDF library, walk through representative findings for each library, and provide PoC snippets.

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Researching Open Source apps for XSS to RCE flaws

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Cross-Site Scripting (XSS) is one of the most commonly encountered attacks in web applications. If an attacker can inject a JavaScript code into the application output, this can lead not only to cookie theft, redirection or phishing, but also in some cases to a complete compromise of the system.

In this article I’ll show how to achieve a Remote Code Execution via XSS on the examples of Evolution CMS, FUDForum, and GitBucket.

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