CVE-2024-5814
📋 TL;DR
This TLS protocol vulnerability allows a malicious TLS 1.2 server to force a TLS 1.3 client with downgrade capability to use an unintended ciphersuite, potentially enabling downgrade attacks. It affects TLS 1.3 clients that support downgrade to TLS 1.2, particularly those using wolfSSL library implementations.
💻 Affected Systems
- wolfSSL
📦 What is this software?
Wolfssl by Wolfssl
⚠️ Risk & Real-World Impact
Worst Case
Man-in-the-middle attacker could downgrade TLS 1.3 connections to weaker TLS 1.2 ciphersuites, potentially enabling decryption of sensitive data or session hijacking.
Likely Case
Selective downgrade attacks in controlled environments where attackers can intercept and manipulate TLS handshakes between vulnerable clients and malicious servers.
If Mitigated
Limited impact if clients only connect to trusted servers or have downgrade protection mechanisms enabled.
🎯 Exploit Status
Exploitation requires the attacker to control a TLS server that the client connects to, and the client must have TLS 1.3 with downgrade capability enabled.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: wolfSSL 5.7.0
Vendor Advisory: https://github.com/wolfSSL/wolfssl/blob/master/ChangeLog.md#add_later
Restart Required: Yes
Instructions:
1. Update wolfSSL to version 5.7.0 or later. 2. Recompile applications using wolfSSL. 3. Restart affected services.
🔧 Temporary Workarounds
Disable TLS 1.2 downgrade
allConfigure TLS 1.3 clients to disable downgrade capability to TLS 1.2
wolfSSL_CTX_set_options(ctx, WOLFSSL_OP_NO_TLSv1_2)
Enforce TLS 1.3 only
allConfigure clients to use TLS 1.3 exclusively without fallback
wolfSSL_CTX_SetMinVersion(ctx, WOLFSSL_TLSV1_3)
wolfSSL_CTX_SetMaxVersion(ctx, WOLFSSL_TLSV1_3)
🧯 If You Can't Patch
- Implement network segmentation to restrict client connections to trusted TLS servers only
- Deploy TLS inspection/proxy solutions that can detect and block malicious downgrade attempts
🔍 How to Verify
Check if Vulnerable:
Check wolfSSL version with: wolfSSL_library_version() or examine compiled binaries for version stringsCheck Version:
wolfSSL_library_version() function call or check package manager: wolfssl --versionVerify Fix Applied:
Verify wolfSSL version is 5.7.0 or later and test TLS connections with downgrade scenarios📡 Detection & Monitoring
Log Indicators:
- Unexpected TLS version downgrades in connection logs
- TLS handshake failures with version mismatch errors
Network Indicators:
- TLS 1.3 ClientHello followed by TLS 1.2 ServerHello from unexpected servers
- Abnormal ciphersuite negotiation patterns
SIEM Query:
tls.version_change AND (src_tls_version="1.3" AND dst_tls_version="1.2") FROM suspicious_servers