Security readout for executives and security teams
Plain-English summary
This flaw can let a remote, unauthenticated attacker fill filesystem space on an affected Cisco IOS XE device until it crashes and reloads. That can interrupt traffic passing through the device. The device may recover after reload, but repeated triggering could extend the outage.
Executive priority
Treat as high priority for network infrastructure teams. This is not a data-theft issue, but it can disrupt routed or switched traffic through affected devices, creating business outage risk if critical paths are exposed.
Technical view
Cisco describes ineffective filesystem resource management in IOS XE. Specific remote actions can cause messages to be written to operating system log files, exhausting available filesystem space. Successful exploitation affects availability only, causing crash and reload; filesystem space is cleared after reload.
Likely exposure
Exposure is limited to affected Cisco IOS XE deployments. The provided bundle explicitly names Cisco IOS XE Software 16.1.1, but the Cisco advisory should be checked for the complete affected release matrix and fixed-release guidance.
Exploitation context
The CVSS vector is network-accessible, low-complexity, unauthenticated, and requires no user interaction. The provided sources do not show CISA KEV listing or active exploitation. Repeated exploitation could cause recurring reloads and extended denial of service.
Researcher notes
This is a CWE-400 resource-consumption issue with availability impact. The reload clears impacted filesystem space, so assessment should focus on version exposure, resilience of critical paths, and evidence of recurring resource exhaustion rather than persistent compromise.
Mitigation direction
- Review Cisco’s advisory for affected releases, fixed software, and any vendor workarounds.
- Prioritize Cisco IOS XE devices carrying critical or internet-reachable network traffic.
- Plan upgrades or mitigations through normal network change control.
- Monitor filesystem utilization, reload events, and operational logs for abnormal exhaustion patterns.
Validation and detection
- Inventory Cisco IOS XE devices and record exact software versions.
- Compare versions against Cisco’s advisory for CVE-2019-12658.
- Check device history for unexplained crashes, reloads, or filesystem exhaustion alerts.
- Confirm monitoring covers filesystem space and repeated reload conditions.
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-400: 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 lookupCVE-2019-12658 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
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/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:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/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 Filesystem Exhaustion 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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.