Security readout for executives and security teams
Plain-English summary
This Cisco IOS XR issue can expose an internal Redis database through TCP port 6379 when the health check RPM is activated. Attackers can remotely access and alter data inside the container, but the source says the sandbox prevents remote code execution or host-system compromise.
Executive priority
Prioritize this above typical medium-severity findings because CISA KEV confirms exploitation. Focus first on exposed Cisco IOS XR infrastructure, especially routing platforms supporting critical network services.
Technical view
The health check RPM in Cisco IOS XR Software opens TCP/6379 by default upon activation, exposing Redis inside the NOSi container. Unauthenticated remote access can allow Redis database reads, writes, and arbitrary file writes within the container filesystem. The reported CVSS is 6.5, but CISA KEV status raises operational urgency.
Likely exposure
Exposure is most likely on Cisco IOS XR systems where the health check RPM is installed and activated, and TCP/6379 is reachable from untrusted or insufficiently segmented networks.
Exploitation context
CISA lists CVE-2022-20821 in the Known Exploited Vulnerabilities catalog, so treat exploitation as confirmed. The provided sources do not include exploit mechanics, affected version ranges, or named fixed releases.
Researcher notes
Evidence supports unauthenticated remote Redis access with container-level database and filesystem impact. The source explicitly says attackers cannot execute remote code or compromise IOS XR host integrity through this issue. Version and fix details are not present in the bundle.
Mitigation direction
- Review Cisco’s advisory for supported fixed releases and mitigation guidance.
- Inventory Cisco IOS XR devices and identify health check RPM activation status.
- Restrict reachability to TCP/6379 from untrusted networks where supported.
- Prioritize remediation for internet-facing or broadly reachable management planes.
- Monitor for unexpected Redis access against affected IOS XR systems.
Validation and detection
- Identify Cisco IOS XR assets in scope.
- Confirm whether the health check RPM is activated on each device.
- Verify TCP/6379 is not reachable from unauthorized network segments.
- Review device exposure paths, especially management and control-plane access.
- Track remediation evidence against Cisco advisory guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2022-20821 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N3.92.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20220520 Cisco IOS XR Software Health Check Open Port VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-20821CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.