Wolfssl: >> Wolfssl >> 5.7.4 Security Vulnerabilities
A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality. In wc_PKCS7_BuildSignedAttributes(), when adding custom signed attributes, the code passes an incorrect capacity value (esd->signedAttribsCount) to EncodeAttributes() instead of the remaining available space in the fixed-size signedAttribs[7] array. When an application sets pkcs7->signedAttribsSz to a value greater than MAX_SIGNED_ATTRIBS_SZ (default 7) minus the number of default attributes already added, EncodeAttributes() writes beyond the array bounds, causing stack memory corruption. In WOLFSSL_SMALL_STACK builds, this becomes heap corruption. Exploitation requires an application that allows untrusted input to control the signedAttribs array size when calling wc_PKCS7_EncodeSignedData() or related signing functions.
CVSS Score
2.2
EPSS Score
0.001
Published
2026-03-19
Integer underflow in wolfSSL packet sniffer <= 5.8.4 allows an attacker to cause a buffer overflow in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by ssl_DecodePacket. The underflow wraps a 16-bit length to a large value that is passed to AEAD decryption routines, causing heap buffer overflow and a crash. An unauthenticated attacker can trigger this remotely via malformed TLS Application Data records.
CVSS Score
2.1
EPSS Score
0.003
Published
2026-03-19
In the OpenSSL compatibility layer implementation, the function RAND_poll() was not behaving as expected and leading to the potential for predictable values returned from RAND_bytes() after fork() is called. This can lead to weak or predictable random numbers generated in applications that are both using RAND_bytes() and doing fork() operations. This only affects applications explicitly calling RAND_bytes() after fork() and does not affect any internal TLS operations. Although RAND_bytes() documentation in OpenSSL calls out not being safe for use with fork() without first calling RAND_poll(), an additional code change was also made in wolfSSL to make RAND_bytes() behave similar to OpenSSL after a fork() call without calling RAND_poll(). Now the Hash-DRBG used gets reseeded after detecting running in a new process. If making use of RAND_bytes() and calling fork() we recommend updating to the latest version of wolfSSL. Thanks to Per Allansson from Appgate for the report.
CVSS Score
7.0
EPSS Score
0.004
Published
2025-07-18
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