Known exploited vulnerability
CVE-2022-20821
The short answer
CVE-2022-20821 affects Cisco Cisco IOS XR Software and is rated medium (CVSS 6.5). CISA added it to the Known Exploited Vulnerabilities catalog on 2022-05-23: attackers are using it, so patch it first.
What it is
A vulnerability in the health check RPM of Cisco IOS XR Software could allow an unauthenticated, remote attacker to access the Redis instance that is running within the NOSi container. This vulnerability exists because the health check RPM opens TCP port 6379 by default upon activation. An attacker could exploit this vulnerability by connecting to the Redis instance on the open port. A successful exploit could allow the attacker to write to the Redis in-memory database, write arbitrary files to the container filesystem, and retrieve information about the Redis database. Given the configuration of the sandboxed container that the Redis instance runs in, a remote attacker would be unable to execute remote code or abuse the integrity of the Cisco IOS XR Software host system.
Weakness: CWE-200.
Severity
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Exploited (CISA KEV)
Yes, since May 23, 2022
Federal due date Jun 13, 2022
EPSS, next 30 days
11%
Higher than 96% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
What CISA says to do
Apply updates per vendor instructions.
Affected products
Cisco IOS XR Software. NVD's record lists the exact affected versions.
References
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK Vendor Advisory
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-20821 US Government Resource
Questions
Is CVE-2022-20821 being exploited?
Yes. CISA added CVE-2022-20821 to its Known Exploited Vulnerabilities catalog on 2022-05-23, with a federal remediation due date of 2022-06-13.
How do I fix CVE-2022-20821?
CISA's required action: Apply updates per vendor instructions.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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