Security readout for executives and security teams
Plain-English summary
This flaw could let an unauthenticated remote attacker bypass authentication to Cisco IOS XE NETCONF or RESTCONF management services. If exposed, the attacker could change or delete device configuration, or trigger a denial of service. For network infrastructure, that creates direct business risk to availability, routing, and security controls.
Executive priority
Treat as urgent for internet-reachable or broadly reachable network infrastructure. The risk is not just device outage; successful exploitation could alter security or routing configuration without valid credentials.
Technical view
CVE-2021-1619 is an AAA flaw in Cisco IOS XE caused by an uninitialized variable. Cisco describes remote unauthenticated exploitation through crafted NETCONF or RESTCONF request sequences, potentially allowing configuration manipulation or memory corruption leading to DoS. CVSS is 9.8 critical.
Likely exposure
Exposure is most likely on Cisco IOS XE devices where NETCONF or RESTCONF management services are enabled, especially if reachable from untrusted networks. The provided bundle does not list affected release ranges.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Cisco’s description supports unauthenticated remote exploitability with high confidentiality, integrity, and availability impact.
Researcher notes
Key evidence gaps are affected version detail, fixed releases, and workaround specifics, which are not present in the provided bundle. Avoid assuming exploitation in the wild without KEV or another cited source.
Mitigation direction
- Review Cisco advisory for affected releases, fixed software, and documented workarounds.
- Prioritize Cisco-recommended remediation for confirmed affected IOS XE devices.
- Reduce NETCONF and RESTCONF management-plane exposure using approved access controls.
- Monitor affected devices for unexpected configuration changes or availability degradation.
Validation and detection
- Inventory Cisco IOS XE devices and identify NETCONF or RESTCONF usage.
- Compare installed releases against Cisco advisory applicability and fixed-release guidance.
- Review network management access paths for untrusted reachability.
- Check device change logs for unexpected configuration modifications.
- Confirm remediation with version evidence and management-plane access review.
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-824: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-1619 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
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:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210922 Cisco IOS XE Software NETCONF and RESTCONF Authentication Bypass VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
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.
Access of Uninitialized Pointer
Access of Uninitialized Pointer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.