CVE-2020-9307
mediumpriority · track · 26EPSS 0.006 · 48 %ileEURUUSEPSS · scored 2026-10-28
Hirschmann OS2, RSP, and RSPE devices before HiOS 08.3.00 allow a denial of service. An unauthenticated, adjacent attacker can cause an infinite loop on one of the HSR ring ports of the device. This effectively breaks the redundancy of the HSR ring. If the attacker can perform the same attack on a second device, the ring is broken into two parts (thus disrupting communication between devices in the different parts).
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
No vendor fix yet; a mitigation is available.
- MitigationAFS660-SRcisa_csaf_ot
Hitachi ABB Power Grids has published an advisory for AFS Series and advises users to update products with available updates. The update removes the vulnerability by modifying the way the switch processes HSR frames.
https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A9269&LanguageCode=en&DocumentPartId=&Action=Launch - MitigationAFS665-SRcisa_csaf_ot
Hitachi ABB Power Grids has published an advisory for AFS Series and advises users to update products with available updates. The update removes the vulnerability by modifying the way the switch processes HSR frames.
https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A9269&LanguageCode=en&DocumentPartId=&Action=Launch
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (8)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- ICSA-21-075-03Hitachi ABB Power Grids AFS Series2021-03-16icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability could cause a denial-of-service condition on one of the ports in a HSR ring.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://assets.belden.com/m/1d01d8d5c1dfa7f0/original/Security-Bulletin-BSECV-2019-08-1v0-EN.pdfPatchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-9307cnnvd
- https://us-cert.cisa.gov/ics/advisories/icsa-21-075-03cnnvd
- https://www.auscert.org.au/bulletins/ESB-2021.0941cnnvd
- https://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/viewcnnvd
- https://www.belden.com/securitycnnvd
- https://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/viewenisa_euvd
- https://www.belden.com/securityenisa_euvd
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