Description

Unauthenticated PHP Object Injection in Tipsy <= 1.6 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-10T20:16:40.510Z",
  "pubdate": "2026-10-10T20:16:40.510Z",
  "executiveSummary": "A critical PHP Object Injection vulnerability exists in Tipsy versions 1.6 and earlier, stemming from the insecure handling of serialized user-supplied input.\nThis vulnerability allows an unauthenticated remote attacker to pass malicious serialized data to the application, which is then unserialized without proper validation or filtering.\nSuccessful exploitation leads to Remote Code Execution (RCE) via PHP object injection, enabling attackers to execute arbitrary system commands, manipulate application logic, or compromise the underlying server infrastructure.\nThe risk is severe as the vulnerability does not require authentication or elevated privileges, making it accessible to any external actor capable of interacting with the vulnerable entry point.\nThe primary risk implication is a total system compromise, including potential data exfiltration, unauthorized modification of sensitive files, and full takeover of the application environment.\nOrganizations relying on affected versions of Tipsy are highly susceptible to automated exploitation attempts targeting this deserialization flaw.",
  "technicalDetails": "The root cause of this vulnerability is the application's reliance on the unserialize() function on unsanitized user-controllable input within the Tipsy codebase. PHP's unserialize() mechanism is inherently dangerous when applied to untrusted data, as it allows the instantiation of arbitrary PHP objects present within the application's scope.\nThe vulnerability occurs because the application fails to validate the structure or the origin of the serialized data before processing it. By crafting a specifically engineered serialized object, an attacker can influence the behavior of the application by triggering magic methods such as __wakeup(), __destruct(), or __toString() within existing classes, a technique commonly referred to as PHP Object Injection.\nThe attack flow begins with the attacker identifying a publicly accessible endpoint or parameter that consumes serialized data. The attacker then constructs a malicious payload containing a serialized object graph designed to leverage 'gadget chains'—a sequence of existing code components within the application's codebase or its dependencies—to achieve arbitrary code execution.\nOnce the payload is transmitted to the server, the application invokes unserialize() on the input. This triggers the instantiation of the attacker-defined objects. By carefully selecting properties and values within the serialized stream, the attacker manipulates the application's execution flow. For example, by controlling the state of an object that interacts with file systems, databases, or command execution functions, the attacker can force the application to perform unauthorized actions.\nBecause the vulnerability is unauthenticated, it presents a significant network exposure risk. An attacker does not need prior knowledge of the internal system state or valid credentials to inject the payload. Upon successful deserialization of the malicious object, the injected logic executes within the security context of the web server process (e.g., www-data).\nPost-exploitation impact includes the ability to install persistent backdoors, pivot deeper into the internal network, steal sensitive configuration files (such as database credentials), or launch further attacks from the compromised server. This class of vulnerability is particularly dangerous in modern PHP environments where third-party libraries and frameworks increase the availability of gadget chains."
}