HOMEVULNERABILITIESCVE-2020-9307
MEDIUM

CVE-2020-9307

CWE-835Published: February 11, 2021· Updated: Jun 17, 2026

6.5
CVSS v3.1

Official Description

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).

NVD Source

Technical Analysis

CVE-2020-9307 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorAdjacent
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

belden1 product(s)
hirschmann hios
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/view
ADVISORYhttps://www.belden.com/security
ADVISORYhttps://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/view
ADVISORYhttps://www.belden.com/security

All References (4)

→
https://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/viewVendor Advisory
→
https://www.belden.com/securityVendor Advisory
→
https://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/viewVendor Advisory
→
https://www.belden.com/securityVendor Advisory

Quick Facts

CVE IDCVE-2020-9307
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-835
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 11, 2021

Related CVEs (CWE-835)

CVE-2017-12990
9.8
CVE-2017-12997
9.8
CVE-2017-12995
9.8
CVE-2018-20784
9.8
CVE-2021-42143
9.1
CVE-2024-43366
9.1

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-9307 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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