One of our valued customers reported a vulnerability in our products, that potentially allows uploading and executing arbitrary files via built-in DAV server used in WebMail Pro and Aurora Corporate. We’re now releasing updates for our products closing this vulnerability, and strongly recommend to upgrade your installations to the latest version.
Below, you’ll find recommendations on how to address the issue on your existing installation of WebMail Pro or Aurora. Please note that while these changes were only tested with version 8.5.3, they should work for previous versions as well.
Before we proceed, we’d like to point out that disabling DAV access on the installation effectively closes the vulnerability, too. That’s done by setting Disabled to true in data/settings/modules/Dav.config.json file. Note that this will not affect the use of web interface or Aurora Mail / Aurora Files mobile apps as they work via API, not DAV. If you’d rather keep DAV enabled, please follow the below guidelines.
- In vendor/afterlogic/dav/lib/DAVServer.php file, locate function exec() and replace its code with:
public function exec()
{
$sRequestUri = empty($_SERVER['REQUEST_URI']) ? '' : \trim($_SERVER['REQUEST_URI']);
if ($this->isModuleEnabled('Dav') && !strpos(urldecode($sRequestUri), '../'))
{
parent::exec();
}
else
{
echo 'Access denied';
}
}
2. In vendor/afterlogic/dav/lib/DAV/Auth/Backend/Basic.php file, locate validateUserPass function and replace the line:
if (class_exists('\\Aurora\\System\\Api') && \Aurora\System\Api::IsValid())
with:
if (class_exists('\\Aurora\\System\\Api') && \Aurora\System\Api::IsValid() && $sUserName !== \Afterlogic\DAV\Constants::DAV_PUBLIC_PRINCIPAL && $sUserName !== \Afterlogic\DAV\Constants::DAV_TENANT_PRINCIPAL)
3. Similarly, in vendor/afterlogic/dav/lib/DAV/Auth/Backend/Digest.php file, locate getDigestHash function and replace the line:
if (class_exists('\\Aurora\\System\\Api') && \Aurora\System\Api::IsValid())
with:
if (class_exists('\\Aurora\\System\\Api') && \Aurora\System\Api::IsValid() && $sUserName !== \Afterlogic\DAV\Constants::DAV_PUBLIC_PRINCIPAL && $sUserName !== \Afterlogic\DAV\Constants::DAV_TENANT_PRINCIPAL)
Since some of our clients still use previous v7 of WebMail and Aurora, we chose to issue a security update for those as well. Note that if you don’t use DAV, you can simply disable it by setting EnableMobileSync to Off in data/settings/settings.xml file.
- In libraries/afterlogic/DAV/Server.php file, before the closing “}” add the following function:
public function exec()
{
$sRequestUri = empty($_SERVER['REQUEST_URI']) ? '' : \trim($_SERVER['REQUEST_URI']);
if (!strpos(urldecode($sRequestUri), '../'))
{
parent::exec();
}
else
{
echo 'Access denied';
}
}
2. In libraries/afterlogic/DAV/Auth/Backend/Basic.php file, locate validateUserPass function and replace the line:
if (class_exists('CApi') && \CApi::IsValid())
with:
if (class_exists('CApi') && \CApi::IsValid() && $sUserName !== \afterlogic\DAV\Constants::DAV_PUBLIC_PRINCIPAL && $sUserName !== \afterlogic\DAV\Constants::DAV_TENANT_PRINCIPAL)
3. Similarly, in libraries/afterlogic/DAV/Auth/Backend/Digest.php file, locate getDigestHash function and replace the line:
if (class_exists('CApi') && \CApi::IsValid())
with:
if (class_exists('CApi') && \CApi::IsValid() && $sUserName !== \afterlogic\DAV\Constants::DAV_PUBLIC_PRINCIPAL && $sUserName !== \afterlogic\DAV\Constants::DAV_TENANT_PRINCIPAL)
Should you require any assistance, please don’t hesitate to contact us.
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