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CVE-2021-25663

HIGH
7.5
CVSS Score
Published: April 22, 2021 at 08:42 PM UTC
Updated: June 17, 2026 at 03:42 AM UTC
7 products affected across 1 vendorNucleus Source CodeNucleus NETCapital VSTAR

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Severity
HIGH7.5
Exploit prediction
EPSS 2%

Description

A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.4), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (All versions including affected IPv6 stack). The function that processes IPv6 headers does not check the lengths of extension header options, allowing attackers to put this function into an infinite loop with crafted length values.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Capital VSTAR· Siemens
95%
All versions
Nucleus NET· Siemens
95%
All versions
Nucleus Readystart· Siemens
95%
v < 2017.02.4v < 4.1.0
Affected range stops below 2017.02.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.1.0, so it looks safe — our inference, not a vendor statement
Nucleus Source Code· Siemens
95%
All versions
Capital Embedded AR Classic· Siemens
60%
v < V2303
Affected range stops below V2303, so it looks safe — our inference, not a vendor statement
Nucleus ReadyStart V3· Siemens
60%
v < V2017.02.4
Affected range stops below V2017.02.4, so it looks safe — our inference, not a vendor statement
Nucleus ReadyStart V4· Siemens
60%
v < V4.1.0
Affected range stops below V4.1.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (3)

Source: [email protected]
https://cert-portal.siemens.com/productcert/html/ssa-248289.html
x_refsource_MISCVendor Advisory
Source: [email protected]
https://cert-portal.siemens.com/productcert/pdf/ssa-248289.pdf
x_refsource_CONFIRMx_refsource_MISCThird Party AdvisoryUS Government Resource
Source: [email protected]
https://us-cert.cisa.gov/ics/advisories/icsa-21-103-05

CVSS

7.5HIGHsiemens
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-835

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