TLS Downgrade Vulnerability in WolfSSL: Potential Exploitation via Malicious Server
Summary
DEBIAN-CVE-2024-5814: A malicious TLS1.2 server can force a TLS1.3 client with downgrade capability to use a ciphersuite that it did not agree to and achieve a successful connection. Affects wolfssl versions < 5.7.2-0.1. Fixed in 5.7.2-0.1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
WolfSSL is a lightweight SSL/TLS library targeted for embedded and RTOS environments. It provides secure communication protocols and is widely used in various applications, including IoT devices. The library supports multiple cryptographic algorithms and is designed for performance and portability. However, it is susceptible to a vulnerability that allows a malicious TLS1.2 server to manipulate a TLS1.3 client, potentially compromising secure connections.
Vulnerability Detail
A malicious TLS1.2 server can exploit a flaw in WolfSSL to force a TLS1.3 client with downgrade capability to use a ciphersuite that it did not agree to, resulting in a successful connection that undermines the security of the communication. This vulnerability arises from the client's failure to fully parse the server hello message, allowing the server to dictate the ciphersuite used in the session. The implications of this vulnerability include unauthorized access to sensitive data and potential man-in-the-middle attacks.
How To Fix
Minimum fixed version
5.7.2-0.1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade wolfsslTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can disable downgrade capabilities in their TLS1.3 clients if feasible, although this may limit compatibility with certain servers. Additionally, ensure that your server configurations enforce strict ciphersuite policies to mitigate potential exploitation.
Conclusion
The TLS downgrade vulnerability in WolfSSL poses significant risks to secure communications, allowing malicious actors to exploit the flaw to dictate ciphersuite usage. It is crucial for users to update to the patched version 5.7.2-0.1 to safeguard their applications. Until an update can be applied, implementing workarounds can help mitigate potential risks.
See every vulnerability recorded for wolfssl →
FAQ
The vulnerability allows a malicious TLS1.2 server to force a TLS1.3 client to use an unauthorized ciphersuite, compromising the security of the connection.
You can use Vulert, which monitors open-source vulnerabilities in your software. By checking your manifest file like package-lock.json, Vulert can alert you to any vulnerabilities, including this one.
The risks include unauthorized access to sensitive data, potential man-in-the-middle attacks, and overall compromise of secure communications.
Yes, the patched version of WolfSSL is 5.7.2-0.1. Users should update to this version to mitigate the vulnerability.
If immediate updates are not possible, consider disabling downgrade capabilities in your TLS1.3 clients and enforcing strict ciphersuite policies on your servers.
References
Related vulnerabilities
Recent vulnerabilities recorded for wolfssl.
