Unauthenticated Redis access via default-open health-check port
Published May 26, 2022 · Updated Oct 21, 2025
Improper access control in Cisco IOS XR Software 7.3.3 allows remote attackers to access the NOSi container's Redis service. The active health check RPM binds Redis to 0.0.0.0 on TCP port 6379 without access controls, exposing the service beyond the container. Only Cisco 8000 Series Routers with the RPM installed and active are affected; attackers can read or write Redis data and write container files, but cannot execute code or alter the IOS XR host.
Summary
What happened
Improper access control in Cisco IOS XR Software 7.3.3 allows remote attackers to access the NOSi container's Redis service. The active health check RPM binds Redis to 0.0.0.0 on TCP port 6379 without access controls, exposing the service beyond the container. Only Cisco 8000 Series Routers with the RPM installed and active are affected; attackers can read or write Redis data and write container files, but cannot execute code or alter the IOS XR host.
The record
- CVE
- CVE-2022-20821
- Published
- May 26, 2022
- Updated
- Oct 21, 2025
- Vendor
- ClamAV
- Product
- Cisco IOS XR Software
- Classifications
- CWE-200, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 1, 2022Exploitation reportedAttempted exploitation in the wild
- May 26, 2022CVE publishedPublication date reported by the CVE source.
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=n/a
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What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Reported exploitation
- Attempted exploitation in the wildreported exploitation
Technologies
Your stack
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Your stack
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