--- title: Azure's Weakest Link – Five Full Cross-Tenant Compromises description: API Connections in Azure Logic Apps let anyone fully compromise any other connection, including Key Vaults and Azure SQL databases, as well as other externally... canonical: https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Azure's Weakest Link – Five Full Cross-Tenant Compromises | daily.dev og:description: API Connections in Azure Logic Apps let anyone fully compromise any other connection, including Key Vaults and Azure SQL databases, as well as other externally... og:url: https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek og:image: https://api.daily.dev/og/posts/bsbsvyrEk.png og:image:alt: Azure's Weakest Link – Five Full Cross-Tenant Compromises 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. # Azure's Weakest Link – Five Full Cross-Tenant Compromises **[Hacker News](https://daily.dev/sources/hn)** · 11 min read · 1 upvotes · 0 comments ## Summary API Connections in Azure Logic Apps let anyone fully compromise any other connection, including Key Vaults and Azure SQL databases, as well as other externally connected services. The researcher found five critical elevation-of-privilege bugs, earning $200,000 total. The core flaw lets an attacker use Azure Resource Manager's DynamicInvoke endpoint to path-traverse into a victim's connection. After Microsoft patched DynamicInvoke, the undocumented sibling function DynamicList was exploited the same way, and the other three were assumed vulnerable. A later bypass abused a hidden host.api.RuntimeUrl parameter and a validation-order bug where checks ran before path normalization. All five reported issues were fixed. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the root cause of the Azure Logic Apps API Connection cross-tenant vulnerability? Azure's API Management instance exchanges an input token for a backend service's configured token without properly verifying ownership of the referenced connection. Using the ARM REST API's DynamicInvoke endpoint with a path traversal payload (like 'path/%2e%2e/%2e%2e/apim/keyvault/.../secrets/...'), an attacker can make the APIM instance operate on a victim's connection instead of their own, gaining its backend token. _Teams auditing Azure Logic Apps for tenant isolation issues can track vulnerability research like this on daily.dev._ ### How did bypassing the DynamicInvoke path traversal fix lead to new Azure vulnerabilities? After Microsoft blocked path traversal on DynamicInvoke, three other undocumented functions reachable on the same API path (including DynamicList) were found vulnerable to the identical exploit technique, since the fix only covered DynamicInvoke. A payload sending separate path parameters through DynamicList achieved an arbitrary cross-tenant SQL write on a victim's Azure SQL database. _Developers tracking how Azure patches propagate across related endpoints can follow write-ups like this on daily.dev._ ### What is the host.api.RuntimeUrl parameter exploit in Azure Logic Apps connections? It is an undocumented parameter that lets a Logic App override the runtimeUrl baked into its referenced connection, as long as the host ends in azure-apihub.net, which still attaches the required Authorization header. Microsoft's first fix validated the runtime URL strictly, but validation ran before path normalization, so a crafted URL still pointed to a victim's APIM backend while passing the check. _Anyone securing Logic Apps integrations can follow new Azure cloud security research on daily.dev._ ## Community take How the wider developer community reacted, aggregated from 1 discussion and 56 comments across hackernews (as of 2026-10-31). **TL;DR:** The discussion is dominated by frustration and mockery of Microsoft/Azure's security track record and support quality, with little pushback defending the company beyond explaining why enterprises stay locked in. **Sentiment:** 5% positive · 15% mixed · 80% skeptical **The case for** - Some acknowledge the researcher's work was impressive and technically demanding. - A few note enterprise lock-in (bundled licensing, data center locality, vendor consolidation) as a rational, not purely lazy, reason to stay on Azure. **The pushback** - Many see this as part of a long pattern of cross-tenant and cloud security failures at Microsoft, citing a long list of prior incidents. - Commenters describe a cycle where a bug is reported, 'fixed' incorrectly, and later reintroduced, calling it a 'clown show'. - Several criticize Microsoft's enterprise support as slow, outsourced, and ineffective despite premium contracts. - One commenter alleges internal culture discourages employees from reporting validation/security issues. - General skepticism that organizational incentives at Microsoft reward fixing root causes rather than papering over symptoms. **By community** - hackernews (skeptical): The thread leans heavily critical, mixing security skepticism with broader complaints about Microsoft's support, culture, and product quality, though a Microsoft engineer does engage constructively on a tangential issue raised in the thread. **Hottest debate:** Whether enterprises keep choosing Azure for rational reasons (bundling, support, data residency) or purely out of inertia and risk-aversion ('no one gets fired for buying Microsoft'). **Open questions** - Will Microsoft's validation-order and endpoint design patterns continue to produce similar path-traversal bugs across other services? - Can increased automated (including LLM-assisted) vulnerability discovery outpace Microsoft's ability to fix underlying architectural issues? **Highlights** > Ok so. Microsoft had an egregious cross-tenant vulnerability (really, how many cross-tenant vulnerabilities did other clouds have?). Vulnerability was reported. They fixed it - incorrectly. Reported again. They fixed it this time... and broke the previous fix. So it's vulnerable again. What a clown show. > — [outworlder on hackernews · 2 comments](https://news.ycombinator.com/item?id=50305833) > Really not surprising given the history of sloppy coding, elementary authentication mistakes, outsourced "support", and anecdotal reports of horrid internal culture over the past few years [2026] Erosion of Trust @ Azure https://news.ycombinator.com/item?id=47616242 https://isolveproblems.substack.com/p/how-microsoft-vaporize... [2026] https://www.microsoft.com/en-us/security/blog/2026/05/18/sto... [2025] https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft... [2025] https://www.securityweek.com/all-microsoft-entra-tenants-wer... [2024] https://www.cloaked.com/post/microsoft-data-breach [2023] https://www.reuters.com/world/us/chinese-hackers-stole-60000... [2023] https://www.wiz.io/blog/storm-0558-compromised-microsoft-key... [2022] https://www.spiceworks.com/it-security/cloud-security/news/m... [2022] https://techcrunch.com/2022/03/23/microsoft-lapsus-hack-sour... [2021] https://www.cpomagazine.com/cyber-security/microsoft-power-a... [2021] https://www.darkreading.com/cloud-security/microsoft-azure-c... And this is just the Azure / O365 stuff - there's been thousands of Windows client/server and Office software exploits across the same time period > — [waz0wski on hackernews](https://news.ycombinator.com/item?id=50306097) > Reporting cross-Tenant issues as an outsider with a vulnerability chain gets you $$$. Reporting “theoretical” issues with validation as an Employee gets you a lot of questions as to why you were looking. Oh well. > — [eugenekay on hackernews · 2 comments](https://news.ycombinator.com/item?id=50303894) > That's me. But I don't understand your comment. Could you expand on it, either in a reply or preferably by email or via an MSRC case? You can reply with the vuln number so I can fast route it. > The callback you're redirecting the user to at the end of that flow is forgeable The redirect_uri is checked against the app registration. There's a general OAuth problem called "open registration redirects" that applies here, about which we've [blogged](https://www.microsoft.com/en-us/security/blog/2026/03/02/oau...) - but frankly, none of the industry solves this well. In general, "I can create a link that goes to malware via X endpoint" isn't very interesting - you can also just create a direct link to the malware. Web browsers won't reliably show you the real destination of a link anyhow and even if they did, it's mostly just us hackers who understand URLs at all. > as long as a way to authenticate users exists. I'm lost. Entra supports [OpenID Connect](https://learn.microsoft.com/en-us/entra/identity-platform/v2...) for authentication. Most portals that surface admin consent authenticate the user with an OpenID Connect request either immediately before or after the admin consent request. > — [wibartle on hackernews](https://news.ycombinator.com/item?id=50311522) > They'll see it, tell a manager, it'll get added as a ticket to an Azure Devops board under the initiative for this month under the epic for employee suggestions, which will be reviewed & prioritised by Copilot and sent to a different middle manager as a weekly summary email and then automatically closed when no human ever interacts with the ticket after three months. > — [birdsongs on hackernews · 1 comments](https://news.ycombinator.com/item?id=50307271) **Source threads** - [hackernews](https://news.ycombinator.com/item?id=50301854) · 260 points · 56 comments ## Similar posts on daily.dev - [CosmosEscape: Taking over Every Database in Azure Cosmos DB](https://daily.dev/posts/cosmosescape-taking-over-every-database-in-azure-cosmos-db-7zp4vevni) · Hacker News · 0 upvotes · 0 comments - [No single pane of glass: Anatomy of an Azure permission takeover](https://daily.dev/posts/no-single-pane-of-glass-anatomy-of-an-azure-permission-takeover-q7x1g2hf6) · Sysdig Blog · 0 upvotes · 0 comments - [How your cloud could get hacked: an analysis of a real-world vulnerability chain](https://daily.dev/posts/how-your-cloud-could-get-hacked-an-analysis-of-a-real-world-vulnerability-chain-fpulkynl5) · Securelist · 0 upvotes · 0 comments - [Microsoft Self-Service Password Reset abused in Azure data theft attacks](https://daily.dev/posts/microsoft-self-service-password-reset-abused-in-azure-data-theft-attacks-wzksyvp0l) · BleepingComputer · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#azure](https://daily.dev/tags/azure), [#vulnerability](https://daily.dev/tags/vulnerability) [View this post on daily.dev](https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek) ```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":"Azure's Weakest Link – Five Full Cross-Tenant Compromises","url":"https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek"},"datePublished":"2026-10-30T13:27:12.343Z","dateModified":"2026-10-31T01:28:22.377Z","description":"API Connections in Azure Logic Apps let anyone fully compromise any other connection, including Key Vaults and Azure SQL databases, as well as other externally...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/62509ed7f3cc0e64185634a173f591fa?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/62509ed7f3cc0e64185634a173f591fa?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hacker News","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hacker News","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/hn","url":"https://daily.dev/sources/hn"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security,azure,vulnerability","timeRequired":"PT11M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hacker News","item":"https://daily.dev/sources/hn"},{"@type":"ListItem","position":3,"name":"Azure's Weakest Link – Five Full Cross-Tenant Compromises"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/azure-s-weakest-link-five-full-cross-tenant-compromises-bsbsvyrek#faq","mainEntity":[{"@type":"Question","name":"What is the root cause of the Azure Logic Apps API Connection cross-tenant vulnerability?","acceptedAnswer":{"@type":"Answer","text":"Azure's API Management instance exchanges an input token for a backend service's configured token without properly verifying ownership of the referenced connection. Using the ARM REST API's DynamicInvoke endpoint with a path traversal payload (like 'path/%2e%2e/%2e%2e/apim/keyvault/.../secrets/...'), an attacker can make the APIM instance operate on a victim's connection instead of their own, gaining its backend token. Teams auditing Azure Logic Apps for tenant isolation issues can track vulnerability research like this on daily.dev."}},{"@type":"Question","name":"How did bypassing the DynamicInvoke path traversal fix lead to new Azure vulnerabilities?","acceptedAnswer":{"@type":"Answer","text":"After Microsoft blocked path traversal on DynamicInvoke, three other undocumented functions reachable on the same API path (including DynamicList) were found vulnerable to the identical exploit technique, since the fix only covered DynamicInvoke. A payload sending separate path parameters through DynamicList achieved an arbitrary cross-tenant SQL write on a victim's Azure SQL database. Developers tracking how Azure patches propagate across related endpoints can follow write-ups like this on daily.dev."}},{"@type":"Question","name":"What is the host.api.RuntimeUrl parameter exploit in Azure Logic Apps connections?","acceptedAnswer":{"@type":"Answer","text":"It is an undocumented parameter that lets a Logic App override the runtimeUrl baked into its referenced connection, as long as the host ends in azure-apihub.net, which still attaches the required Authorization header. Microsoft's first fix validated the runtime URL strictly, but validation ran before path normalization, so a crafted URL still pointed to a victim's APIM backend while passing the check. Anyone securing Logic Apps integrations can follow new Azure cloud security research on daily.dev."}}]} ```