Exploitation evidence
Known exploited · CISA KEV listed
Added 2022-05-23. Ransomware campaign use: Unknown.
CISA required action: Apply updates per vendor instructions.
CISA due date: 2022-06-13. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Cisco / Cisco IOS XR Software
Default status: Not specified
- affected: n/a
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.11471,
"percentile": 0.96075
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.11471,
"percentile": 0.96049
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.11471,
"percentile": 0.96044
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.11471,
"percentile": 0.96043
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.11471,
"percentile": 0.9604
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.11471,
"percentile": 0.96034
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.11471,
"percentile": 0.96031
}05 Nov 2026, 06:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
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"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"name": "20220520 Cisco IOS XR Software Health Check Open Port Vulnerability",
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"x_refsource_CISCO",
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"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK"
}
],
"title": "CVE Program Container"
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{
"metrics": [
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"content": {
"id": "CVE-2022-20821",
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{
"Technical Impact": "partial"
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"timestamp": "2024-10-29T16:11:07.480784Z",
"version": "2.0.3"
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},
{
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],
"timeline": [
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"time": "2022-05-23T00:00:00.000Z",
"value": "CVE-2022-20821 added to CISA KEV"
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],
"title": "CISA ADP Vulnrichment"
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],
"cna": {
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"versions": [
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],
"datePublic": "2022-05-20T00:00:00.000Z",
"descriptions": [
{
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"value": "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."
}
],
"exploits": [
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],
"metrics": [
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"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
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],
"source": {
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"defect": [
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},
"title": "Cisco IOS XR Software Health Check Open Port Vulnerability",
"x_legacyV4Record": {
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"STATE": "PUBLIC",
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},
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{
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{
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}
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},
"exploit": [
{
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"value": "In May 2022, the Cisco PSIRT became aware of attempted exploitation of this vulnerability in the wild. Cisco strongly recommends that customers apply suitable workaround or upgrade to a fixed software release to remediate this vulnerability."
}
],
"impact": {
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"datePublished": "2022-05-26T14:00:31.613Z",
"dateReserved": "2021-11-02T00:00:00.000Z",
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"state": "PUBLISHED"
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}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.11471,
"percentile": 0.96028
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.11471,
"percentile": 0.9602
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.11471,
"percentile": 0.96015
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2022-20821",
"cwes": [
"CWE-923"
],
"dateAdded": "2022-05-23",
"dueDate": "2022-06-13",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://nvd.nist.gov/vuln/detail/CVE-2022-20821",
"product": "IOS XR",
"requiredAction": "Apply updates per vendor instructions.",
"shortDescription": "Cisco IOS XR software health check opens TCP port 6379 by default on activation. An attacker can connect to the Redis instance on the open port and allow access to the Redis instance that is running within the NOSi container.",
"vendorProject": "Cisco",
"vulnerabilityName": "Cisco IOS XR Open Port Vulnerability"
}