Security readout for executives and security teams
Plain-English summary
This Cisco IOS XE issue can let a remote unauthenticated attacker crash and reload an affected network device, causing an outage. The attack depends on TrustSec PAC provisioning and a specific device state, so urgency is lower than broadly exploitable router takeover flaws, but affected edge or access devices can still disrupt business operations.
Executive priority
Handle through normal network vulnerability remediation, with faster action for critical routing, switching, or access-control devices. The main business risk is service disruption, not data theft, based on the provided sources.
Technical view
CVE-2019-12663 is improper input validation in the Cisco TrustSec Protected Access Credential provisioning module. Malformed RADIUS message attributes can trigger an IOS XE device reload, producing denial of service. CVSS is 6.8 with network attack vector, high complexity, no privileges, no user interaction, changed scope, and high availability impact.
Likely exposure
Exposure is most likely in environments running Cisco IOS XE with Cisco TrustSec CTS PAC provisioning and RADIUS integration. The source bundle does not identify specific affected releases, so product owners must map Cisco IOS XE inventory against Cisco's advisory.
Exploitation context
The CVE record describes remote unauthenticated exploitation, but only while the device is in a specific state. The bundle marks CISA KEV as false and provides no cited evidence of active exploitation or public exploit use.
Researcher notes
The key uncertainty is affected version scope; the bundle lists Cisco IOS XE Software but does not enumerate releases. Do not assume exploit activity. Validation should focus on TrustSec PAC provisioning state, RADIUS exposure, IOS XE release mapping, and reload telemetry.
Mitigation direction
- Review Cisco's advisory for affected releases, fixed releases, and official upgrade guidance.
- Prioritize remediation for IOS XE devices supporting critical network paths.
- Restrict RADIUS traffic to trusted authentication infrastructure using existing network controls.
- If CTS PAC provisioning is unused, evaluate disabling it with Cisco guidance.
- Monitor affected devices for unexpected reloads until remediation is complete.
Validation and detection
- Inventory Cisco IOS XE devices and identify TrustSec CTS PAC provisioning usage.
- Compare IOS XE versions and configurations against Cisco's advisory.
- Confirm RADIUS communication is limited to expected trusted servers.
- Review availability logs for unexplained reloads near RADIUS or TrustSec activity.
- Track remediation status for each affected network device owner.
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
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CWE-20: Exact CWE lookup
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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-2019-12663 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
- 6.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/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:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H2.24Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.8MediumVector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20190925 Cisco IOS XE Software TrustSec Protected Access Credential Provisioning Denial of Service 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.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.