wolfSSL has released version 5.8.2, a security-focused point update that addresses four newly disclosed vulnerabilities, extends several hardening features, and introduces a long list of functional improvements and platform ports.
Below is a technical breakdown of the most critical changes shipping in the July 2025 build.
The headline issue fixed in 5.8.2 is a logic vulnerabilities affecting builds that enable both WOLFSSL_SYS_CA_CERTS and WOLFSSL_APPLE_NATIVE_CERT_VALIDATION on iOS, iPadOS, watchOS or tvOS targets.
When these options were compiled in (either manually or by default on non-macOS Apple platforms), the wolfSSL layer delegated final verification to Apple native trust store.
That call unintentionally overwrote any earlier certificate errors reported by wolfSSL—such as hostname mismatch, stale OCSP response or revoked certificate—allowing a valid chain in the system keychain to trump wolfSSL’s own checks and keep the TLS handshake alive.
In practice, an attacker controlling one trusted CA certificate (or abusing a compromised subordinate) could present an otherwise invalid leaf certificate and still obtain a successful connection.
The patch ensures that native-store validation no longer suppresses wolfSSL errors and that the connection is aborted when any failure is detected earlier in the chain.
wolfSSL Patches Key Vulnerabilities
- Fault-Injection Protection (ECC / Ed25519) – Researchers demonstrated a single-bit fault attack capable of flipping branch decisions in the verify code path.
- A mis-compare could trick embedded bootloaders such as wolfBoot into accepting a forged signature. wolfSSL 5.8.2 adds a compile-time mitigation (
--enable-faultharden) and turns on extra verification consistency checks by default. - RAND after
fork()(CVE-2025-7394) – When wolfSSL’s OpenSSL compatibility layer exposedRAND_bytes()inside a multi-process application, child processes inherited the parent’s DRBG state. - Predictable post-fork output could threaten applications that call
RAND_bytes()directly (TLS itself remained unaffected). The new release reseeds its Hash-DRBG automatically upon PID change and alignsRAND_poll()semantics with upstream OpenSSL behavior. - Curve25519 Blinding Default (CVE-2025-7396) – Blinding support added in 5.8.0 is now enabled by default in C implementations to mask private operations against power-analysis and timing leakage.
- Blinding is unnecessary on arm/intel assembly or the “small” Curve25519 build, but can be disabled explicitly if needed.
New Platforms and Performance Tweaks
Beyond security patches, 5.8.2 continues the library’s rapid platform expansion:
- Linux Kernel Module – AES, SHA and HMAC are now fully implemented in the LKM, and DH / FFDHE registration is complete, boosting in-kernel TLS performance.
- Post-Quantum Crypto – ML-KEM (Kyber) integrates an updated ARM file for Zephyr; Dilithium interoperability code now supports OpenSSL-formatted keys.
- STM32N6, PPC-32 SHA-256, ESP32P4 and STM32 WBA receive first-class ports, while SHA-256 assembly landed for PowerPC 32.
- Default Settings Changes – MD5 is disabled in both Autotools and CMake builds. The project also flags
--enable-heapmathas deprecated and removes long-standing DTLS examples that still relied on insecure cipher suites.
The changelog lists more than 120 PRs touching build-system quality-of-life (CMake presets, STM32Cube fixes, improved GCC 4.8 compatibility), expanded coverage testing, and additional ASN.1 and PKCS #7 APIs.
Developers should noted that the GPL re-licensing announced in 5.8.2 moves the project to GPLv3—existing GPLv2 integrators must either upgrade licensing or pin to 5.8..
Upgrade guidance: Any deployment that (a) runs wolfSSL on Apple hardware, (b) relies on RAND_bytes() after fork(), or (c) performs signature verification on potentially hostile media should patch immediately.
As usual, rebuild third-party applications against the new headers/libraries and retest mutual-auth handshakes—particularly if session resumption or system CA validation is involved.
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