cisco-sa-20190417-iosxracl
Vulnerability from csaf_cisco
Published
2019-04-17 16:00
Modified
2019-04-17 16:00
Summary
Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability
Notes
Summary
A vulnerability in the TCP flags inspection feature for access control lists (ACLs) on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device.
The vulnerability is due to incorrect processing of the ACL applied to an interface of an affected device when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. An attacker could exploit this vulnerability by sending traffic through an affected device that should otherwise be denied by the configured ACL. An exploit could allow the attacker to bypass protection offered by a configured ACL on the affected device.
There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl"]
Vulnerable Products
This vulnerability affects Cisco ASR 9000 Series Aggregation Services Routers only when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. This capability is not enabled by default.
For information about affected configurations and software releases, consult the Cisco bug ID(s) at the top of this advisory.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products ["#vp"] section of this advisory are known to be affected by this vulnerability.
Workarounds
If the 5-tuple hash algorithm is used for load balancing, the device is not affected by the vulnerability described in this advisory.
If the 3-tuple hash algorithm is required, enabling ACL compression for the ACL on the interface is a workaround for this vulnerability.
Fixed Software
For information about fixed software releases ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"], consult the Cisco bug ID(s) at the top of this advisory.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page ["https://www.cisco.com/go/psirt"], to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
Exploitation and Public Announcements
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
Source
This vulnerability was found during the resolution of a Cisco TAC support case.
Legal Disclaimer
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.
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An exploit could allow the attacker to bypass protection offered by a configured ACL on the affected device.\r\n\r\nThere are workarounds that address this vulnerability.\r\n\r\nThis advisory is available at the following link:\r\nhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl\"]", "title": "Summary" }, { "category": "general", "text": "This vulnerability affects Cisco ASR 9000 Series Aggregation Services Routers only when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. This capability is not enabled by default.\r\n\r\nFor information about affected configurations and software releases, consult the Cisco bug ID(s) at the top of this advisory.", "title": "Vulnerable Products" }, { "category": "general", "text": "Only products listed in the Vulnerable Products [\"#vp\"] section of this advisory are known to be affected by this vulnerability.", "title": "Products Confirmed Not Vulnerable" }, { "category": "general", "text": "If the 5-tuple hash algorithm is used for load balancing, the device is not affected by the vulnerability described in this advisory.\r\n\r\nIf the 3-tuple hash algorithm is required, enabling ACL compression for the ACL on the interface is a workaround for this vulnerability.", "title": "Workarounds" }, { "category": "general", "text": "For information about fixed software releases [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes\"], consult the Cisco bug ID(s) at the top of this advisory.\r\n\r\nWhen considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page [\"https://www.cisco.com/go/psirt\"], to determine exposure and a complete upgrade solution.\r\n\r\nIn all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.", "title": "Fixed Software" }, { "category": "general", "text": "To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html\"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.", "title": "Vulnerability Policy" }, { "category": "general", "text": "The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.", "title": "Exploitation and Public Announcements" }, { "category": "general", "text": "This vulnerability was found during the resolution of a Cisco TAC support case.", "title": "Source" }, { "category": "legal_disclaimer", "text": "THIS DOCUMENT IS PROVIDED ON AN \"AS IS\" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.\r\n\r\nA standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.", "title": "Legal Disclaimer" } ], "publisher": { "category": "vendor", "contact_details": "Emergency Support:\r\n+1 877 228 7302 (toll-free within North America)\r\n+1 408 525 6532 (International direct-dial)\r\nNon-emergency Support:\r\nEmail: psirt@cisco.com\r\nSupport requests that are received via e-mail are typically acknowledged within 48 hours.", "issuing_authority": "Cisco product security incident response is the responsibility of the Cisco Product Security Incident Response Team (PSIRT). The Cisco PSIRT is a dedicated, global team that manages the receipt, investigation, and public reporting of security vulnerability information that is related to Cisco products and networks. The on-call Cisco PSIRT works 24x7 with Cisco customers, independent security researchers, consultants, industry organizations, and other vendors to identify possible security issues with Cisco products and networks.\r\nMore information can be found in Cisco Security Vulnerability Policy available at https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html", "name": "Cisco", "namespace": "https://wwww.cisco.com" }, "references": [ { "category": "self", "summary": "Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability", "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl" }, { "category": "external", "summary": "Cisco Security Vulnerability Policy", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html" }, { "category": "external", "summary": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl", "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl" }, { "category": "external", "summary": "fixed software releases", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes" }, { "category": "external", "summary": "Cisco Security Advisories and Alerts page", "url": "https://www.cisco.com/go/psirt" }, { "category": "external", "summary": "Security Vulnerability Policy", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html" } ], "title": "Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability", "tracking": { "current_release_date": "2019-04-17T16:00:00+00:00", "generator": { "date": "2022-09-03T03:15:14+00:00", "engine": { "name": "TVCE" } }, "id": "cisco-sa-20190417-iosxracl", "initial_release_date": "2019-04-17T16:00:00+00:00", "revision_history": [ { "date": "2019-04-16T16:48:37+00:00", "number": "1.0.0", "summary": "Initial public release." } ], "status": "final", "version": "1.0.0" } }, "product_tree": { "branches": [ { "branches": [ { "category": "product_family", "name": "Cisco IOS XR Software", "product": { "name": "Cisco IOS XR Software ", "product_id": "CSAFPID-5834" } }, { "category": "product_family", "name": "Cisco ASR 9000 Series Aggregation Services Routers", "product": { "name": "Cisco ASR 9000 Series Aggregation Services Routers ", "product_id": "CSAFPID-202356" } } ], "category": "vendor", "name": "Cisco" } ] }, "vulnerabilities": [ { "cve": "CVE-2019-1686", "ids": [ { "system_name": "Cisco Bug ID", "text": "CSCvm01102" } ], "notes": [ { "category": "other", "text": "Complete.", "title": "Affected Product Comprehensiveness" } ], "product_status": { "known_affected": [ "CSAFPID-202356", "CSAFPID-5834" ] }, "release_date": "2019-04-17T16:00:00+00:00", "remediations": [ { "category": "vendor_fix", "details": "Cisco has released software updates that address this vulnerability.", "product_ids": [ "CSAFPID-5834", "CSAFPID-202356" ], "url": "https://software.cisco.com" }, { "category": "workaround", "details": "If the 5-tuple hash algorithm is used for load balancing, the device is not affected by the vulnerability described in this advisory.\r\n\r\nIf the 3-tuple hash algorithm is required, enabling ACL compression for the ACL on the interface is a workaround for this vulnerability.", "product_ids": [ "CSAFPID-202356", "CSAFPID-5834" ] } ], "scores": [ { "cvss_v3": { "baseScore": 5.8, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N", "version": "3.0" }, "products": [ "CSAFPID-202356", "CSAFPID-5834" ] } ], "title": "Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability" } ] }
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- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.