CVE-2025-3416: OpenSSL Use-After-Free Vulnerability

CVE-2025-3416 Overview

A use-after-free vulnerability has been identified in OpenSSL's handling of the properties argument in certain functions. This flaw can lead to undefined behavior or incorrect property parsing, potentially causing OpenSSL to treat the input as an empty string. The vulnerability affects the rust-openssl bindings library, which provides Rust-safe interfaces to the OpenSSL cryptographic library.

Critical Impact

Exploitation of this use-after-free vulnerability may result in undefined behavior, incorrect cryptographic property parsing, or denial of service conditions in applications using affected versions of the rust-openssl library.

Affected Products

• rust-openssl versions prior to 0.10.72
• openssl-sys versions prior to 0.9.107
• Applications using affected rust-openssl bindings with OpenSSL

Discovery Timeline

• April 8, 2025 - CVE-2025-3416 published to NVD
• April 9, 2025 - Last updated in NVD database

Technical Details for CVE-2025-3416

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption flaw that occurs when a program continues to use a pointer after it has been freed. In the context of OpenSSL's properties argument handling, this manifests when certain functions attempt to access memory that has already been deallocated.

The exploitation path involves network-based access with high complexity requirements, as the attacker must craft specific inputs that trigger the use-after-free condition. While no authentication is required and user interaction is not necessary, the complexity of exploitation significantly limits real-world attack feasibility.

When successfully exploited, this vulnerability primarily impacts system availability rather than confidentiality or integrity. The affected OpenSSL functions may incorrectly parse property arguments, treating the freed memory content as an empty string, leading to unexpected application behavior or crashes.

Root Cause

The root cause lies in improper memory management within the rust-openssl bindings when handling the properties argument passed to OpenSSL functions. The library failed to properly maintain ownership of memory buffers, resulting in scenarios where freed memory could be subsequently accessed during property parsing operations. This is a classic use-after-free pattern where the Rust code's interaction with the underlying C OpenSSL library did not properly account for memory lifetime guarantees.

Attack Vector

The attack vector is network-based, meaning an attacker could potentially trigger this vulnerability remotely. However, the high attack complexity requirement indicates that specific conditions must be met for successful exploitation. The attacker would need to:

1. Identify an application using a vulnerable version of rust-openssl
2. Craft malicious input that triggers property parsing in affected functions
3. Time the attack to coincide with the specific memory state required for the use-after-free condition

The following patch demonstrates the version update that addresses this vulnerability:

 [package]
 name = "openssl"
-version = "0.10.71"
+version = "0.10.72"
 authors = ["Steven Fackler <sfackler@gmail.com>"]
 license = "Apache-2.0"
 description = "OpenSSL bindings"

Source: GitHub Commit 87085bd67896

Detection Methods for CVE-2025-3416

Indicators of Compromise

• Unexpected application crashes in services utilizing rust-openssl for cryptographic operations
• Memory corruption errors or segmentation faults in OpenSSL-dependent Rust applications
• Anomalous behavior in property parsing functions, particularly empty string handling where values were expected

Detection Strategies

• Audit Cargo.lock files for rust-openssl versions below 0.10.72 or openssl-sys versions below 0.9.107
• Implement runtime monitoring for use-after-free patterns using memory sanitizers (AddressSanitizer)
• Deploy application-level logging to detect unexpected empty string results from OpenSSL property parsing

Monitoring Recommendations

• Monitor application logs for cryptographic operation failures or unexpected behavior patterns
• Implement crash reporting and analysis for Rust applications using OpenSSL bindings
• Use dependency scanning tools to identify vulnerable rust-openssl versions in your software supply chain

How to Mitigate CVE-2025-3416

Immediate Actions Required

• Update rust-openssl to version 0.10.72 or later immediately
• Update openssl-sys to version 0.9.107 or later
• Review and rebuild all applications using affected rust-openssl versions
• Audit your Cargo dependency tree using cargo audit to identify vulnerable packages

Patch Information

The vulnerability has been addressed in rust-openssl version 0.10.72 and openssl-sys version 0.9.107. The fix was implemented in GitHub Pull Request #2390 and merged in commit 87085bd67896. Additional details are available in the RustSec Advisory RUSTSEC-2025-0022 and the Red Hat CVE-2025-3416 Advisory.

Workarounds

• If immediate patching is not possible, consider isolating affected applications from untrusted network input
• Implement input validation and sanitization before passing data to OpenSSL property parsing functions
• Deploy runtime memory protection mechanisms where available to detect and mitigate use-after-free conditions

# Update rust-openssl to patched version
cargo update -p openssl
cargo update -p openssl-sys

# Verify the update
cargo audit

# Rebuild application
cargo build --release