Out-of-bounds write via unbounded RSA modulus in NetX Secure X.509
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
Eclipse ThreadX - NetX Duo through 6.5.1.202602 contains an out-of-bounds write in the NetX Secure X.509 parser. The parser accepts RSA public keys of any size, but signature verification decrypts into buffers sized for 4096-bit moduli, so a larger modulus writes past a file-scope static (CWE-787). An unauthenticated remote attacker can trigger this with an oversized key in a presented certificate chain, during TLS or DTLS client verification or server client-certificate authentication.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
The X.509 parser in NetX Secure accepts an RSA public key of any size, but every signature-verification path decrypts into fixed-size buffers dimensioned for the `NX_CRYPTO_MAX_RSA_MODULUS_SIZE` default of 4096 bits. A certificate carrying a larger modulus drives an out-of-bounds write past a file-scope static during ordinary certificate-chain verification. It is reachable pre-authentication. The issuer used for the crypto operation is looked up in the remote, peer-supplied store before the trusted store, so the attacker supplies the oversized key themselves as an intermediate in the chain they present. It triggers on a TLS or DTLS client verifying a malicious server's chain, and on a server performing client-certificate authentication.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Eclipse Foundation | Eclipse ThreadX - NetX Duo | up to 6.5.1.202602 | 6.5.2.202603 | Patch available | CNA |
- Eclipse ThreadX - NetX Duo VendorEclipse Foundation Affected up to 6.5.1.202602 Fixed in 6.5.2.202603 Patch available CNA
Remediation
Update Eclipse ThreadX - NetX Duo to version 6.5.2.202603, the fixed version listed for this flaw.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Eclipse ThreadX - NetX Duo (Eclipse Foundation) Fixed in 6.5.2.202603
Timeline
- 2026-10-20 Threatist record created from CVE-2026-93475
- 2026-10-20 CISA SSVC decision points changed
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Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences