Security readout for executives and security teams
Plain-English summary
This is a critical Cisco IOS and IOS XE flaw. A remote unauthenticated attacker can send crafted traffic to an affected device and potentially take control with elevated privileges or force a reload, causing outage. Because CISA lists it in KEV, treat it as a known-exploited network infrastructure risk.
Executive priority
Treat as urgent. This affects core network infrastructure, has critical severity, requires no authentication, and is listed by CISA as known exploited. Prioritize exposed devices first and track remediation to closure.
Technical view
The QoS subsystem incorrectly bounds-checks values in packets destined to UDP port 18999 on affected Cisco IOS and IOS XE devices. Processing malicious device-destined packets can trigger a buffer overflow, enabling elevated arbitrary code execution or device reload. Transit traffic alone does not trigger the issue.
Likely exposure
Exposure is most likely where affected Cisco IOS or IOS XE devices can receive traffic to UDP port 18999. Internet-facing or broadly reachable network infrastructure is highest concern. The bundle does not enumerate exact affected releases or fixed versions.
Exploitation context
CISA KEV inclusion supports known exploitation. The CVSS 9.8 vector indicates network access, low complexity, no privileges, and no user interaction. Sources do not provide exploit details here, and none are needed for defensive prioritization.
Researcher notes
Key scoping detail: packets must be destined to and processed by the affected device; transiting traffic is not sufficient. Evidence in the bundle identifies Cisco Bug ID CSCvf73881, CWE-119, CVSS 9.8, and KEV status, but not exact fixed versions.
Mitigation direction
- Check Cisco advisory cisco-sa-20180328-qos for affected and fixed software guidance.
- Prioritize remediation for internet-facing or widely reachable Cisco IOS and IOS XE devices.
- Limit device-destined UDP port 18999 exposure where operationally feasible.
- Monitor affected devices for unexpected reloads or suspicious device-destined UDP traffic.
- Confirm CISA KEV handling timelines apply to regulated environments.
Validation and detection
- Inventory Cisco IOS and IOS XE devices and record software versions.
- Determine whether each device can receive UDP port 18999 traffic.
- Map exposed devices against Cisco advisory affected-release guidance.
- Review logs and monitoring for unexpected reloads or abnormal UDP 18999 traffic.
- Document remediation status and remaining exceptions.
Public sources used
Michael Williams reviewed this cited source version on .
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-119: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-0151 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
- Yes
- 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.
CISA KEV status
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
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-03CVE reference · x_refsource_MISC
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-qosCVE reference · x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0151CVE reference · government-resource
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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.