CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
Percentile
52.8%
Successful exploitation of this vulnerability could cause a denial-of-service condition where the affected web servers wait for the completion of each request, occupying all available HTTP connections. The web server recovers by itself once the attack ends.
Siemens reports this vulnerability affects the following RUGGEDCOM ROS switches and serial-to-Ethernet devices:
Affected Siemens RUGGEDCOM ROS devices improperly handle partial HTTP requests, which makes them vulnerable to slowloris attacks. This could allow a remote attacker to create a denial-of-service condition that persists until the attack ends.
CVE-2022-39158 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated. the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).
Siemens reported these vulnerabilities to CISA.
Siemens identified the following specific workarounds and mitigations users can apply to reduce risk:
As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemensβ operational guidelines for industrial security, and to follow the recommendations in the product manuals.
Siemens provides additional information on industrial security on the Siemens website.
For further inquiries on security vulnerabilities in Siemensβ products and solutions, users should contact Siemens ProductCERT.
For more information see the associated Siemens security advisory SSA-787941 in HTML and CSAF.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability these vulnerabilities. Specifically, users should:
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage at cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01BβTargeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability. This vulnerability is exploitable remotely. This vulnerability has a low attack complexity.
cert-portal.siemens.com/productcert/csaf/ssa-787941.json
cert-portal.siemens.com/productcert/html/ssa-787941.html
cisa.gov/ics
cisa.gov/ics
cisasurvey.gov1.qualtrics.com/jfe/form/SV_9n4TtB8uttUPaM6?product=https://www.cisa.gov/news-events/ics-advisories/icsa-22-314-05
cwe.mitre.org/data/definitions/400.html
new.siemens.com/global/en/products/services/cert.html#SecurityPublications
nvd.nist.gov/vuln/detail/CVE-2022-39158
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
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us-cert.cisa.gov/ics/Recommended-Practices
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01
www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B
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www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
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www.oig.dhs.gov/
www.siemens.com/cert/advisories
www.siemens.com/cert/operational-guidelines-industrial-security
www.siemens.com/industrialsecurity
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www.whitehouse.gov/
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