Writeup Exploits

46,637 exploits tracked across all sources.

Sort: Activity Stars
CVE-2020-24585 WRITEUP MEDIUM
wolfSSL <4.5.0 - Info Disclosure
An issue was discovered in the DTLS handshake implementation in wolfSSL before 4.5.0. Clear DTLS application_data messages in epoch 0 do not produce an out-of-order error. Instead, these messages are returned to the application.
CVSS 5.3
CVE-2020-24585 WRITEUP MEDIUM
wolfSSL <4.5.0 - Info Disclosure
An issue was discovered in the DTLS handshake implementation in wolfSSL before 4.5.0. Clear DTLS application_data messages in epoch 0 do not produce an out-of-order error. Instead, these messages are returned to the application.
CVSS 5.3
CVE-2020-15309 WRITEUP HIGH
wolfSSL <4.5.0 - Info Disclosure
An issue was discovered in wolfSSL before 4.5.0, when single precision is not employed. Local attackers can conduct a cache-timing attack against public key operations. These attackers may already have obtained sensitive information if the affected system has been used for private key operations (e.g., signing with a private key).
CVSS 7.0
CVE-2020-12457 WRITEUP HIGH
wolfSSL <4.5.0 - DoS
An issue was discovered in wolfSSL before 4.5.0. It mishandles the change_cipher_spec (CCS) message processing logic for TLS 1.3. If an attacker sends ChangeCipherSpec messages in a crafted way involving more than one in a row, the server becomes stuck in the ProcessReply() loop, i.e., a denial of service.
CVSS 7.5
CVE-2020-12457 WRITEUP HIGH
wolfSSL <4.5.0 - DoS
An issue was discovered in wolfSSL before 4.5.0. It mishandles the change_cipher_spec (CCS) message processing logic for TLS 1.3. If an attacker sends ChangeCipherSpec messages in a crafted way involving more than one in a row, the server becomes stuck in the ProcessReply() loop, i.e., a denial of service.
CVSS 7.5
CVE-2020-11735 WRITEUP MEDIUM
Wolfssl < 4.4.0 - Information Disclosure
The private-key operations in ecc.c in wolfSSL before 4.4.0 do not use a constant-time modular inverse when mapping to affine coordinates, aka a "projective coordinates leak."
CVSS 5.3
CVE-2020-11713 WRITEUP HIGH
Wolfssl - Information Disclosure
wolfSSL 4.3.0 has mulmod code in wc_ecc_mulmod_ex in ecc.c that does not properly resist timing side-channel attacks.
CVSS 7.5
CVE-2019-6439 WRITEUP CRITICAL
Wolfssl < 3.15.7 - Out-of-Bounds Write
examples/benchmark/tls_bench.c in a benchmark tool in wolfSSL through 3.15.7 has a heap-based buffer overflow.
CVSS 9.8
CVE-2019-19963 WRITEUP MEDIUM
wolfSSL <4.3.0 - Info Disclosure
An issue was discovered in wolfSSL before 4.3.0 in a non-default configuration where DSA is enabled. DSA signing uses the BEEA algorithm during modular inversion of the nonce, leading to a side-channel attack against the nonce.
CVSS 5.3
CVE-2019-19962 WRITEUP HIGH
Wolfssl < 4.3.0 - Signature Verification Bypass
wolfSSL before 4.3.0 mishandles calls to wc_SignatureGenerateHash, leading to fault injection in RSA cryptography.
CVSS 7.5
CVE-2019-19960 WRITEUP MEDIUM
wolfSSL <4.3.0 - Info Disclosure
In wolfSSL before 4.3.0, wc_ecc_mulmod_ex does not properly resist side-channel attacks.
CVSS 5.3
CVE-2019-18840 WRITEUP HIGH
wolfSSL <4.2.0c - Buffer Overflow
In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer overflow inside the DecodedCert structure in GetName in wolfcrypt/src/asn.c because the domain name location index is mishandled. Because a pointer is overwritten, there is an invalid free.
CVSS 7.5
CVE-2019-16748 WRITEUP CRITICAL
wolfSSL <4.1.0 - Buffer Overflow
In wolfSSL through 4.1.0, there is a missing sanity check of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer over-read in CheckCertSignature_ex in wolfcrypt/src/asn.c.
CVSS 9.8
CVE-2019-15651 WRITEUP CRITICAL
Wolfssl - Out-of-Bounds Read
wolfSSL 4.1.0 has a one-byte heap-based buffer over-read in DecodeCertExtensions in wolfcrypt/src/asn.c because reading the ASN_BOOLEAN byte is mishandled for a crafted DER certificate in GetLength_ex.
CVSS 9.8
CVE-2018-16870 WRITEUP MEDIUM
wolfssl <3.15.7 - Info Disclosure
It was found that wolfssl before 3.15.7 is vulnerable to a new variant of the Bleichenbacher attack to perform downgrade attacks against TLS. This may lead to leakage of sensible data.
CVSS 5.9
CVE-2017-8855 WRITEUP HIGH
wolfSSL <3.11.0 - Buffer Overflow
wolfSSL before 3.11.0 does not prevent wc_DhAgree from accepting a malformed DH key.
CVSS 7.5
CVE-2017-8854 WRITEUP HIGH
Wolfssl < 3.10.0a - Memory Corruption
wolfSSL before 3.10.2 has an out-of-bounds memory access with loading crafted DH parameters, aka a buffer overflow triggered by a malformed temporary DH file.
CVSS 7.8
CVE-2017-6076 WRITEUP MEDIUM
Wolfssl < 3.10.2 - Information Disclosure
In versions of wolfSSL before 3.10.2 the function fp_mul_comba makes it easier to extract RSA key information for a malicious user who has access to view cache on a machine.
CVSS 5.5
CVE-2017-13099 WRITEUP HIGH
Wolfssl < 3.12.2 - Information Disclosure
wolfSSL prior to version 3.12.2 provides a weak Bleichenbacher oracle when any TLS cipher suite using RSA key exchange is negotiated. An attacker can recover the private key from a vulnerable wolfSSL application. This vulnerability is referred to as "ROBOT."
CVSS 7.5
CVE-2026-4395 WRITEUP CRITICAL
Heap-based buffer overflow in wc_ecc_import_x963_ex KCAPI path
Heap-based buffer overflow in the KCAPI ECC code path of wc_ecc_import_x963_ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkey_raw buffer via a crafted oversized EC public key point. The WOLFSSL_KCAPI_ECC code path copies the input to key->pubkey_raw (132 bytes) using XMEMCPY without a bounds check, unlike the ATECC code path which includes a length validation. This can be triggered during TLS key exchange when a malicious peer sends a crafted ECPoint in ServerKeyExchange.
CVSS 9.8
CVE-2026-4159 WRITEUP LOW
wc_PKCS7_DecodeEnvelopedData 1 byte out-of-bounds read
1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.
CVE-2026-3849 WRITEUP CRITICAL
Buffer Overflow in HPKE via Oversized ECH Config
Stack Buffer Overflow in wc_HpkeLabeledExtract via Oversized ECH Config. A vulnerability existed in wolfSSL 5.8.4 ECH (Encrypted Client Hello) support, where a maliciously crafted ECH config could cause a stack buffer overflow on the client side, leading to potential remote execution and client program crash. This could be exploited by a malicious TLS server supporting ECH. Note that ECH is off by default, and is only enabled with enable-ech.
CVSS 9.8
CVE-2026-3580 WRITEUP LOW
Compiler-induced timing leak in sp_256_get_entry_256_9 on RISC-V
In wolfSSL 5.8.4, constant-time masking logic in sp_256_get_entry_256_9 is optimized into conditional branches (bnez) by GCC when targeting RISC-V RV32I with -O3. This transformation breaks the side-channel resistance of ECC scalar multiplication, potentially allowing a local attacker to recover secret keys via timing analysis.
CVE-2026-3579 WRITEUP LOW
Non-constant time multiplication subroutine __muldi3 on RISC-V RV32I
wolfSSL 5.8.4 on RISC-V RV32I architectures lacks a constant-time software implementation for 64-bit multiplication. The compiler-inserted __muldi3 subroutine executes in variable time based on operand values. This affects multiple SP math functions (sp_256_mul_9, sp_256_sqr_9, etc.), leading to a timing side-channel that may expose sensitive cryptographic data.
CVE-2026-3549 WRITEUP CRITICAL
wolfSSL < 5.9.0 - Heap Buffer Overflow in TLS 1.3 ECH Parsing
Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.
CVSS 9.8