CVE-2021-25664
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.88%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 the Hop-by-Hop extension header in IPv6 packets and its options lacks any checks against the length field of the header, allowing attackers to put the function into an infinite loop by supplying arbitrary length values.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 1.88% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-835
- Affected
- siemens/capital vstar · siemens/nucleus net · siemens/nucleus readystart v3 · siemens/nucleus readystart v4 · siemens/nucleus source code
- Source
- productcert@siemens.com
EPSS 1.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://cert-portal.siemens.com/productcert/html/ssa-248289.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-248289.pdfVendor Advisory
- https://us-cert.cisa.gov/ics/advisories/icsa-21-103-05Third Party Advisory, US Government Resource
- https://cert-portal.siemens.com/productcert/html/ssa-248289.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-248289.pdfVendor Advisory
- https://us-cert.cisa.gov/ics/advisories/icsa-21-103-05Third Party Advisory, US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.