{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/configuration-corruption/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["nginx-ui"],"_cs_severities":["high"],"_cs_tags":["race-condition","nginx-ui","denial-of-service","remote-code-execution","configuration-corruption"],"_cs_type":"advisory","_cs_vendors":["0xJacky"],"content_html":"\u003cp\u003eThe \u003ccode\u003enginx-ui\u003c/code\u003e application, specifically version v2.3.3, is susceptible to a race condition stemming from the lack of synchronization mechanisms and non-atomic file writes within its settings update pipeline. This vulnerability, identified on Kali Linux 6.17.10-1kali1 within a Docker container deployment, arises when multiple concurrent requests modify the primary configuration file (\u003ccode\u003eapp.ini\u003c/code\u003e). This leads to memory and file corruption resulting in inconsistent application states. This vulnerability can lead to persistent denial-of-service conditions and, under specific circumstances, introduces a non-deterministic path for achieving remote code execution through the cross-contamination of configuration parameters. Defenders should be aware of the potential for disrupted nginx-ui services, especially in environments with frequent configuration updates.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains access to the nginx-ui dashboard, likely through valid credentials or exploiting an existing vulnerability.\u003c/li\u003e\n\u003cli\u003eThe attacker navigates to the settings or preferences section of the nginx-ui.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a POST request to the \u003ccode\u003e/api/settings\u003c/code\u003e endpoint with malicious settings modifications using tools such as Burp Suite.\u003c/li\u003e\n\u003cli\u003eThe attacker floods the \u003ccode\u003e/api/settings\u003c/code\u003e endpoint with multiple concurrent requests to trigger the race condition.\u003c/li\u003e\n\u003cli\u003eDue to the lack of synchronization primitives, \u003ccode\u003eProtectedFill()\u003c/code\u003e modifies shared global singleton pointers in an unsafe manner.\u003c/li\u003e\n\u003cli\u003eConcurrent write operations to \u003ccode\u003eapp.ini\u003c/code\u003e interleave, causing file corruption with empty lines, truncated fields, or overwritten configuration keys.\u003c/li\u003e\n\u003cli\u003eThe corruption of \u003ccode\u003eapp.ini\u003c/code\u003e causes the application to either redirect to the \u003ccode\u003e/install\u003c/code\u003e page or encounter a fatal error during boot, leading to a denial of service.\u003c/li\u003e\n\u003cli\u003eIf configuration sections become interleaved (e.g., nginx settings written into webauthn section), an attacker might inject a malicious payload into a command execution field such as \u003ccode\u003eReloadCmd\u003c/code\u003e, achieving potential remote code execution upon the next nginx reload.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe race condition in \u003ccode\u003enginx-ui\u003c/code\u003e can have significant consequences. The immediate impact is a persistent denial of service, rendering the application unavailable. The corruption of the \u003ccode\u003eapp.ini\u003c/code\u003e file leads to loss of configuration integrity, making recovery through the web UI impossible. Furthermore, the potential for cross-contamination of INI values opens a non-deterministic path to remote code execution. Although the conditions for achieving RCE are dependent on the precise interleaving of thread execution, successful exploitation would allow an attacker to execute arbitrary commands on the server.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the patched version of nginx-ui (v2.3.4) available at \u003ca href=\"https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.4\"\u003ehttps://github.com/0xJacky/nginx-ui/releases/tag/v2.3.4\u003c/a\u003e to remediate CVE-2026-33028.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for multiple, rapid \u003ccode\u003ePOST\u003c/code\u003e requests to the \u003ccode\u003e/api/settings\u003c/code\u003e endpoint to detect potential exploitation attempts.\u003c/li\u003e\n\u003cli\u003eImplement a file integrity monitoring (FIM) system to detect unauthorized modifications to the \u003ccode\u003eapp.ini\u003c/code\u003e configuration file using file_event logs.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule to detect suspicious processes invoking the \u003ccode\u003enginx -s reload\u003c/code\u003e command after settings modification to identify potential RCE attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-08T12:00:00Z","date_published":"2024-01-08T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-08-nginx-ui-race-condition/","summary":"The nginx-ui application is vulnerable to a race condition due to concurrent requests corrupting the app.ini configuration file, potentially leading to a persistent denial of service and a non-deterministic path to remote code execution.","title":"nginx-ui Race Condition Leads to Data Corruption and Potential RCE","url":"https://feed.craftedsignal.io/briefs/2024-01-08-nginx-ui-race-condition/"}],"language":"en","title":"CraftedSignal Threat Feed - Configuration-Corruption","version":"https://jsonfeed.org/version/1.1"}