CVE-2020-6994
highpriority · track · 40EPSS 0.016 · 76 %ileEURUUSEPSS · scored 2026-10-27
A buffer overflow vulnerability was found in some devices of Hirschmann Automation and Control HiOS and HiSecOS. The vulnerability is due to improper parsing of URL arguments. An attacker could exploit this vulnerability by specially crafting HTTP requests to overflow an internal buffer. The following devices using HiOS Version 07.0.02 and lower are affected: RSP, RSPE, RSPS, RSPL, MSP, EES, EES, EESX, GRS, OS, RED. The following devices using HiSecOS Version 03.2.00 and lower are affected: EAGLE20/30.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
No vendor fix yet; a mitigation is available.
- MitigationEAGLE20/30cisa_csaf_ot
Hirschmann also recommends, as a workaround, users either use the “IP Access Restriction” feature to restrict HTTP and HTTPS to trusted IP addresses, or disable the HTTP and HTTPS server.
- MitigationRSP RSPE RSPS RSPL MSP EES EES EESX GRS OS REDcisa_csaf_ot
Hirschmann also recommends, as a workaround, users either use the “IP Access Restriction” feature to restrict HTTP and HTTPS to trusted IP addresses, or disable the HTTP and HTTPS server.
- MitigationHitachi Energy AFF660 FWcisa_csaf_ot
Disable the HTTP and HTTPS server.
- MitigationHitachi Energy AFF665 FWcisa_csaf_ot
Disable the HTTP and HTTPS server.
- MitigationAFS660/AFS665cisa_csaf_ot
Hitachi Energy recommends users update to 7.1.05 or later or apply mitigation strategies.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (14)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- ICSA-20-091-01Hirschmann Automation and Control HiOS and HiSecOS Products2020-03-31icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability could allow an unauthenticated, remote attacker to overflow a buffer and fully compromise the device.
- ICSA-22-263-02Hitachi Energy AFF660/665 Series2022-09-20icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability could overflow a buffer on the device and fully compromise it.
- ICSA-22-270-01Hitachi Energy AFS660/AFS6652022-09-27icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability could allow an attacker to overflow an internal buffer and fully compromise the target device.
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://nvd.nist.gov/vuln/detail/CVE-2020-6994cnnvd
- https://us-cert.cisa.gov/ics/advisories/icsa-22-263-02cnnvd
- https://us-cert.cisa.gov/ics/advisories/icsa-22-270-01cnnvd
- https://www.auscert.org.au/bulletins/ESB-2022.4662cnnvd
- https://www.auscert.org.au/bulletins/ESB-2022.4802cnnvd
- https://www.belden.com/hubfs/support/security/bulletins/Belden_Security_Bulletin_BSECV-2020-01_1v2_FINAL.pdfPatchcnnvd
- https://www.us-cert.gov/ics/advisories/icsa-20-091-01cnnvd
- https://www.us-cert.gov/ics/advisories/icsa-20-091-01enisa_euvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan