https://feed.craftedsignal.io/products/vvveb--1.0.8.3/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioThu, 14 May 2026 15:17:40 +0000https://feed.craftedsignal.io/briefs/2026-05-vvveb-file-upload/Thu, 14 May 2026 15:17:40 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-05-vvveb-file-upload/Vvveb before 1.0.8.3 is vulnerable to unrestricted file upload, allowing super_admin users to execute arbitrary PHP code by uploading a malicious plugin ZIP file containing PHP code which is then accessible via HTTP requests.Vvveb is vulnerable to an unrestricted file upload vulnerability (CVE-2026-41937) affecting versions prior to 1.0.8.3. The vulnerability exists in the plugin upload endpoint, allowing super_admin users to upload arbitrary files. An attacker can exploit this by crafting a malicious plugin ZIP file containing a plugin.php file with a valid Slug header, alongside a public/index.php file containing arbitrary PHP code. Upon uploading this malicious plugin, the PHP code within public/index.php becomes accessible via unauthenticated HTTP requests to the plugin’s public path, resulting in remote code execution (RCE) as the web server user.

Attack Chain

1. An attacker identifies a Vvveb instance running a version prior to 1.0.8.3.
2. The attacker authenticates as a super_admin user.
3. The attacker crafts a malicious ZIP archive containing two files: plugin.php and public/index.php.
4. The plugin.php file includes a valid Slug header to bypass initial checks.
5. The public/index.php file contains arbitrary PHP code intended for execution.
6. The attacker uploads the crafted ZIP file through the plugin upload endpoint.
7. The Vvveb application extracts the ZIP file, placing the public/index.php in a publicly accessible directory.
8. The attacker sends an unauthenticated HTTP request to the public/index.php file’s URL, triggering the execution of the embedded PHP code on the server.

Impact

Successful exploitation of this vulnerability leads to arbitrary PHP code execution on the Vvveb server. This allows an attacker with super_admin privileges to gain complete control of the affected Vvveb instance, potentially leading to data breaches, defacement, or further lateral movement within the network. Due to the unrestricted nature of the file upload, attackers can deploy backdoors, execute system commands, and compromise the confidentiality, integrity, and availability of the application and underlying system.

Recommendation

• Upgrade Vvveb to version 1.0.8.3 or later to patch CVE-2026-41937.
• Implement the Sigma rule “Detect CVE-2026-41937 Exploitation Attempt — Vvveb Plugin Upload” to detect malicious plugin uploads based on HTTP request characteristics.
• Restrict access to the plugin upload endpoint to authorized personnel only.
• Monitor web server logs for suspicious activity, particularly requests to newly uploaded PHP files.

]]>highadvisoryfile uploadremote code executionweb applicationhttps://feed.craftedsignal.io/briefs/2026-05-vvveb-recursion-dos/Thu, 14 May 2026 15:17:27 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-05-vvveb-recursion-dos/Vvveb before version 1.0.8.3 is vulnerable to an uncontrolled recursion vulnerability in the admin controller dispatch cycle that allows a low-privilege attacker to cause denial of service by exhausting PHP memory.Vvveb is susceptible to an uncontrolled recursion vulnerability (CVE-2026-41935) affecting versions prior to 1.0.8.3. The vulnerability lies within the admin controller dispatch cycle, specifically how Base::init() repeatedly invokes permission() on error handlers. This recursion occurs when a low-privilege account attempts to access forbidden admin URLs. By sending sustained requests, an attacker can exhaust the PHP memory on all workers, leading to a denial-of-service condition that impacts legitimate traffic. This vulnerability poses a significant risk to web applications using Vvveb, as even a low-privilege account can trigger a widespread outage.

Attack Chain

1. Attacker obtains a low-privilege account on the Vvveb application.
2. Attacker identifies forbidden admin URLs (e.g., /admin/config).
3. Attacker crafts HTTP requests targeting these forbidden admin URLs.
4. The requests are sent to the Vvveb server.
5. The server’s admin controller dispatch cycle initiates.
6. Due to insufficient permissions, Base::init() invokes permission() on error handlers.
7. The error handler triggers a recursive call back to permission(), repeating infinitely.
8. This uncontrolled recursion exhausts PHP memory limits on all workers, causing a denial-of-service condition.

Impact

Successful exploitation of this vulnerability leads to a denial-of-service condition affecting all users of the Vvveb application. While the vulnerability requires a low-privilege account, the resulting impact can be severe, potentially disrupting critical services and causing financial losses. The CVSS v3.1 base score is 7.1, indicating a high risk of exploitation and potential damage. The number of affected victims depends on the popularity and deployment size of the Vvveb instance.

Recommendation

• Upgrade Vvveb to version 1.0.8.3 or later to patch CVE-2026-41935; reference the advisory in the references section.
• Deploy the Sigma rule “Detect CVE-2026-41935 Exploitation Attempt - Multiple 403 Errors” to identify potential exploitation attempts by monitoring web server logs for frequent 403 errors.
• Monitor web server resource consumption (CPU, memory) for unexpected spikes, which could indicate a denial-of-service attack stemming from the uncontrolled recursion.

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