ASN1SCC is an open source ASN.1 compiler for embedded systems

Why it is Yellow

• CVSS 8.1 high
• Remotely exploitable without logging in

References

• https://github.com/esa/asn1scc/commit/fe6ab763bc60d8a2def4104c15414809b45fffd9
• https://github.com/esa/asn1scc/releases/tag/4.7.0.1
• https://github.com/esa/asn1scc/security/advisories/GHSA-825c-7h77-2jjq

Original description

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.