Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2022-20821 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Cisco Ios Xr. Its CVSS base score is 6.5 (Medium).
Operationally, ranked in the top 4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A vulnerability in the health check RPM of Cisco IOS XR Software allows unauthenticated remote access to a Redis instance running inside the NOSi container. The issue stems from the RPM opening TCP port 6379 by default when activated, exposing the database without authentication controls. The affected component is therefore the health-check functionality within IOS XR rather than the core routing stack.
An unauthenticated remote attacker can connect directly to the exposed Redis port and perform write operations against the in-memory database, write arbitrary files inside the container filesystem, or enumerate database metadata. Because the container is sandboxed, these actions do not extend to remote-code execution or compromise of the underlying IOS XR host.
Cisco’s security advisory at tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK details mitigation steps, and the vulnerability appears in CISA’s Known Exploited Vulnerabilities catalog.
EPSS scores rose from low values to a peak of 0.2041 before receding to the current 0.0884, indicating a period of increased exploitation interest after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-26071
Vulnerability Data
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…
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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.
- CWE(s)
- KEV Date Added
- 23 May 2022
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.
Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.
Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.
By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.
Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.
Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.
Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.
Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.5.10 only requires awareness, a topic-specific acceptable-use policy stating expected behaviours/monitoring, and procedures referencing classification and other controls; per the owner's explicit rule on labelling and similar dependency-style clauses, this does not itself prevent exposure (CWE-200) unless access/DLP/etc. act on it.
Requiring the return of all physical and electronic assets plus secure deletion of organizational data from personal devices reduces the chance that sensitive information remains accessible to departing personnel.
A.5.12 only defines and communicates a classification scheme so that protection needs can be understood; per the owner's explicit rule, labeling/classification does not itself prevent exposure and requires other controls (e.g. access enforcement) to act on it.
By requiring classification labels and metadata on all information assets, the control makes it harder for sensitive data to be inadvertently exposed because downstream systems and users can recognize and enforce handling rules based on those labels.
Requiring encryption, access controls, and recipient authentication for transfers directly reduces the chance that sensitive data reaches an unauthorized observer.
Secure delivery, protected storage, and confidentiality of allocation records limit exposure of authentication material to unauthorized observers.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.