Vvveb CMS - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/products/vvveb-cms/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioTue, 02 Jan 2024 12:00:00 +0000Vvveb CMS v1.0.8 Remote Code Execution via File Renamehttps://feed.craftedsignal.io/briefs/2024-01-vvveb-rce/Tue, 02 Jan 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-vvveb-rce/Vvveb CMS v1.0.8 is vulnerable to remote code execution due to a missing return statement in the file rename handler, allowing authenticated attackers to bypass extension restrictions and execute arbitrary code by manipulating .htaccess and .php files.Vvveb CMS v1.0.8 is susceptible to a remote code execution vulnerability (CVE-2026-6257) within its media management component. The flaw stems from a missing return statement in the file rename handler, which fails to properly restrict file extensions during renaming operations. This oversight allows authenticated attackers to bypass intended security measures and rename files to potentially dangerous extensions, such as .php or .htaccess. This vulnerability allows attackers to inject Apache directives and subsequently execute arbitrary code on the server. Successful exploitation grants the attacker the same privileges as the web server user (www-data), potentially leading to full system compromise.

Attack Chain

  1. An attacker authenticates to the Vvveb CMS application with valid credentials.
  2. The attacker uploads a benign text file (e.g., "test.txt") through the media management interface.
  3. The attacker leverages the vulnerable file rename functionality to rename "test.txt" to ".htaccess".
  4. The attacker injects malicious Apache directives into the ".htaccess" file. This is done to associate PHP execution with other file extensions (e.g., image files) or to directly inject PHP code.
  5. The attacker uploads another benign file, such as an image file ("evil.jpg").
  6. The attacker renames "evil.jpg" to "evil.php" (or another extension configured in the .htaccess file).
  7. When "evil.php" is accessed via a web request, the injected Apache directives cause the file to be parsed as PHP code.
  8. The attacker executes arbitrary operating system commands with the privileges of the web server user (www-data).

Impact

Successful exploitation of this vulnerability allows an attacker to execute arbitrary code on the affected Vvveb CMS server. The attacker gains the same privileges as the web server user (www-data), potentially leading to sensitive data disclosure, modification of website content, or full system compromise. Given the CVSS v3.1 base score of 9.1, this vulnerability poses a critical risk to organizations using the affected Vvveb CMS version.

Recommendation

  • Apply the patch or upgrade to a non-vulnerable version of Vvveb CMS to remediate CVE-2026-6257.
  • Monitor web server logs for suspicious file rename requests targeting ".htaccess" or ".php" extensions using the provided Sigma rule.
  • Implement strict file extension validation on the server side to prevent unauthorized file renaming.
  • Review and restrict Apache directives to prevent injection of malicious configurations via .htaccess files.
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