esa ASN1SCC prior 4.7.0.1 BitStream Decoder asn1crt_encoding.c BitStream_DecodeConstraintWholeNumber heap-based overflow

Summaryinfo

A vulnerability was found in esa ASN1SCC. It has been rated as critical. This affects the function BitStream_DecodeConstraintWholeNumber of the file asn1crt/asn1crt_encoding.c of the component BitStream Decoder. The manipulation leads to heap-based overflow. This vulnerability is listed as CVE-2026-75614. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in esa ASN1SCC. This issue affects the function BitStream_DecodeConstraintWholeNumber of the file asn1crt/asn1crt_encoding.c of the component BitStream Decoder. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, BitStream_DecodeConstraintWholeNumber in asn1crt/asn1crt_encoding.c reads enough bits for a constrained integer but does not reject values above the declared range when the encoded range is not a power of two. Generated uPER and ACN decoders for variable-size SEQUENCE OF, OCTET STRING, BIT STRING, and string values use the invalid result as a loop or copy length, so a crafted over-range size field can write beyond a destination buffer. Decoding untrusted affected data can corrupt heap or stack memory, cause a crash, or potentially permit code execution. This issue is fixed in version 4.7.0.1.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-75614 since 08/18/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 4.7.0.1 eliminates this vulnerability.

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Productinfo

Vendor

• esa

Name

• ASN1SCC

Website

• Product: https://github.com/esa/asn1scc/

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