FKIE_CVE-2026-102758
Vulnerability from fkie_nvd - Published: 2026-09-29 18:17 - Updated: 2026-09-30 21:17
Severity
Summary
The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks out of DER-encoded data. It is the primitive underneath all X.509 certificate parsing in NetX Secure, and therefore runs on certificates supplied by a remote peer during the TLS handshake.
The function reads the one-byte ASN.1 tag from the caller's buffer *before* checking that the buffer holds at least one byte. When a caller passes a remaining length of zero, the guard correctly returns `NX_SECURE_X509_ASN1_LENGTH_TOO_LONG`, but the read has already happened one byte past the end of the buffer.
code:
nx_secure/src/nx_secure_x509_asn1_tlv_block_parse.c
```
UINT _nx_secure_x509_asn1_tlv_block_parse(const UCHAR *buffer, ULONG *buffer_length, USHORT *tlv_type,
USHORT *tlv_tag_class, ULONG *tlv_length,
const UCHAR **tlv_data, ULONG *header_length)
{
UINT current_index;
USHORT current_tag;
ULONG length;
ULONG length_bytes;
current_index = 0;
current_tag = buffer[current_index]; /* <-- read before the bounds check */
if (*buffer_length < 1)
{
return(NX_SECURE_X509_ASN1_LENGTH_TOO_LONG);
}
```
The remainder of the function is correctly ordered. The multi-byte length path is guarded by `length_bytes > 4 || length_bytes > *buffer_length` before its read loop, the decoded value is checked against `length > *buffer_length`, and the second single-byte length read follows its own `*buffer_length < 1` guard. The tag read is the only load placed ahead of its check.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"packageName": "NetX Duo",
"product": "NetX Duo",
"vendor": "Eclipse Foundation",
"versions": [
{
"lessThanOrEqual": "6.5.1.202602",
"status": "affected",
"version": "0",
"versionType": "custom"
},
{
"status": "unaffected",
"version": "6.5.2.202603"
}
]
}
],
"source": "emo@eclipse.org"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks out of DER-encoded data. It is the primitive underneath all X.509 certificate parsing in NetX Secure, and therefore runs on certificates supplied by a remote peer during the TLS handshake.\n\n\n\nThe function reads the one-byte ASN.1 tag from the caller\u0027s buffer *before* checking that the buffer holds at least one byte. When a caller passes a remaining length of zero, the guard correctly returns `NX_SECURE_X509_ASN1_LENGTH_TOO_LONG`, but the read has already happened one byte past the end of the buffer.\n\n\n\ncode:\n\n\n\nnx_secure/src/nx_secure_x509_asn1_tlv_block_parse.c\n\n\n\n```\n\n\n\nUINT _nx_secure_x509_asn1_tlv_block_parse(const UCHAR *buffer, ULONG *buffer_length, USHORT *tlv_type,\n\n USHORT *tlv_tag_class, ULONG *tlv_length,\n const UCHAR **tlv_data, ULONG *header_length)\n\n\n{\n\n\n\nUINT current_index;\n\n\n\nUSHORT current_tag;\n\n\n\nULONG length;\n\n\n\nULONG length_bytes;\n\n current_index = 0;\n current_tag = buffer[current_index]; /* \u003c-- read before the bounds check */\n if (*buffer_length \u003c 1)\n {\n return(NX_SECURE_X509_ASN1_LENGTH_TOO_LONG);\n }\n\n\n```\n\n\n\nThe remainder of the function is correctly ordered. The multi-byte length path is guarded by `length_bytes \u003e 4 || length_bytes \u003e *buffer_length` before its read loop, the decoded value is checked against `length \u003e *buffer_length`, and the second single-byte length read follows its own `*buffer_length \u003c 1` guard. The tag read is the only load placed ahead of its check."
}
],
"id": "CVE-2026-102758",
"lastModified": "2026-09-30T21:17:05.347",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-102758",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-30T20:42:14.455455Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-09-29T18:17:13.047",
"references": [
{
"source": "emo@eclipse.org",
"url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-f95g-xc4w-mrcr"
}
],
"sourceIdentifier": "emo@eclipse.org",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-126"
}
],
"source": "emo@eclipse.org",
"type": "Secondary"
}
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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