--- title: MAD Bugs: Even "cat readme.txt" is not safe | daily.dev description: A security vulnerability in iTerm2 allows arbitrary code execution simply by running `cat readme.txt`. The bug stems from iTerm2's SSH integration feature,... canonical: https://daily.dev/posts/mad-bugs-even-cat-readme-txt-is-not-safe-yf8mujkpy twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: MAD Bugs: Even "cat readme.txt" is not safe | daily.dev og:description: A security vulnerability in iTerm2 allows arbitrary code execution simply by running `cat readme.txt`. The bug stems from iTerm2's SSH integration feature,... og:url: https://daily.dev/posts/mad-bugs-even-cat-readme-txt-is-not-safe-yf8mujkpy og:image: https://api.daily.dev/og/posts/YF8MuJKPy.png og:image:alt: MAD Bugs: Even "cat readme.txt" is not safe og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # MAD Bugs: Even "cat readme.txt" is not safe **[Hacker News](https://daily.dev/sources/hn)** · 6 min read · 0 upvotes · 0 comments ## Summary A security vulnerability in iTerm2 allows arbitrary code execution simply by running `cat readme.txt`. The bug stems from iTerm2's SSH integration feature, which uses terminal escape sequences (DCS 2000p and OSC 135) as a protocol between iTerm2 and a remote conductor script. Because iTerm2 doesn't verify that these sequences come from a trusted source, a malicious file can embed forged conductor protocol messages. When displayed via `cat`, iTerm2 processes the fake conductor transcript, walks through its SSH integration state machine, and ultimately writes base64-encoded commands to the PTY — one of which resolves to an attacker-controlled executable path. The bug was reported March 30 and fixed in commit a9e745993c2e on March 31, though the fix had not yet reached stable releases at time of writing. The discovery was AI-assisted, in collaboration with OpenAI. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [From Indirect Prompt Injection to DNS Exfiltration in macOS Terminal · Embrace The Red](https://daily.dev/posts/from-indirect-prompt-injection-to-dns-exfiltration-in-macos-terminal-embrace-the-red-g5b1m75zv) · Embrace The Red · 1 upvotes · 0 comments - [Sandbox bypass flaws in Cursor IDE highlight prompt injection as an RCE vector](https://daily.dev/posts/sandbox-bypass-flaws-in-cursor-ide-highlight-prompt-injection-as-an-rce-vector-fnfy3vrj6) · CSO Online · 0 upvotes · 0 comments - [Coding Agent Horror Stories: The Command You Already Approved](https://daily.dev/posts/coding-agent-horror-stories-the-command-you-already-approved-wjc417ezn) · Docker · 0 upvotes · 0 comments --- Tags: [#ssh](https://daily.dev/tags/ssh) [View this post on daily.dev](https://daily.dev/posts/mad-bugs-even-cat-readme-txt-is-not-safe-yf8mujkpy) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"MAD Bugs: Even \"cat readme.txt\" is not safe","url":"https://daily.dev/posts/mad-bugs-even-cat-readme-txt-is-not-safe-yf8mujkpy","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/mad-bugs-even-cat-readme-txt-is-not-safe-yf8mujkpy"},"datePublished":"2026-04-18T01:51:21.133Z","dateModified":"2026-04-18T01:51:44.019Z","description":"A security vulnerability in iTerm2 allows arbitrary code execution simply by running `cat readme.txt`. 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