Abusing the $method argument of Client::send, it was possible to force the client to access local files or connect to undesired urls instead of the intended target server's url (the one used in the Client constructor).
This weakness only affects installations where all the following conditions apply, at the same time:
$method argument of method Client::send(), in conjunction with conditions which trigger usage of curl as http transport (ie. either using the https, http11 or http2 protocols, or calling Client::setUseCurl() beforehand)return_type property to 'xml', or make the resulting Response's object httpResponse member, which is intended to be used for debugging purposes only, available to 3rd parties, eg. by displaying it to the end user or serializing it in some storage (note that the same data can also be accessed via magic property Response::raw_data, and in the Request's httpResponse member)This is most likely a very uncommon usage scenario, and as such the chances of exploitation of this issue may be low.
If it is not possible to upgrade to this release of the library at this time, a proactive security measure, to avoid the Client accessing any local file on the server which hosts it, is to add the following call to your code:
$client->setCurlOptions([CURLOPT_PROTOCOLS, CURLPROTO_HTTPS|CURLPROTO_HTTP]);
Originally reported as issue #81
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.