Cista Insecure Deserialization Vulnerability Leading to Memory Address Leak

A vulnerability exists in Cista versions through 0.15, allowing for insecure deserialization of untrusted input. Under certain conditions, this flaw can lead to the leakage of stack or heap addresses, which may be exploited to bypass Address Space Layout Randomization (ASLR). The issue arises from insufficient checks in the 'cista::raw' namespace, where classes with pointer-like mechanics are vulnerable to reference tampering. Cista fails to adequately validate self-referencing pointers and references to other data within the payload. The address leak occurs if the deserialized values are observable by the attacker.

Impact

Exploitation of this vulnerability can lead to unauthorized memory address disclosure, allowing an attacker to bypass ASLR and potentially facilitate further attacks, such as code execution or exploitation of other vulnerabilities that rely on knowledge of memory addresses.

Reproduction

The vulnerability can be reproduced by serializing a structure that includes a pointer-like reference, such as a 'data::ptr' or 'data::unique_ptr', to an object within the same structure. After serialization, the deserialization process can be manipulated to create a self-referencing pointer that leaks its own address. This can be done by crafting the serialized data to overwrite the pointer's reference with an address offset that points to itself, effectively bypassing ASLR protections. Additionally, the vulnerability can be demonstrated using 'data::vector' or 'data::indexed_vector' to reference arbitrary addresses within the payload, further exploiting the deserialization process.

Remediation

To address this vulnerability, Cista should implement stricter validation checks during the deserialization process to prevent self-referencing pointers and unauthorized references to other data within the payload. Additionally, maintaining a hashmap of 'seen' addresses to track and validate pointer references could help prevent type confusion and ensure that unique pointers do not reference the same memory location multiple times.