Security readout for executives and security teams
Plain-English summary
This flaw can let a remote, unauthenticated attacker disrupt some IPv4 traffic through affected Cisco Remote PHY devices by sending malformed IPv4 fragments. For operators using Remote PHY, the business impact is service degradation or outage. The source bundle does not provide CVSS, affected versions, fixed releases, or confirmed exploitation.
Executive priority
Treat as a service-availability risk for networks dependent on Cisco Remote PHY. Prioritize validation in production provider environments, but urgency cannot be precisely rated from the supplied sources because severity, fixed versions, and exploit evidence are missing.
Technical view
Cisco describes improper validation and calculation of numerical values in IPv4 packets handled by certain Remote PHY Software fragment-processing functions. Malformed IPv4 traffic sent to an affected device may disrupt transit IPv4 traffic and cause denial of service. The record maps to CWE-399, but version and remediation details are not included in the provided bundle.
Likely exposure
Exposure is likely limited to environments running Cisco Remote PHY Software on affected devices that process IPv4 traffic. Cable, broadband, or service-provider networks using Remote PHY should verify product and software release details against Cisco guidance.
Exploitation context
The source states exploitation is remote and unauthenticated using malformed IPv4 traffic. The bundle does not include exploit availability, observed exploitation, or inclusion in CISA KEV. KEV is marked false, so active exploitation should not be assumed.
Researcher notes
The useful validation path is asset and release confirmation, not exploit reproduction. The public description identifies IPv4 fragment-processing logic and numeric validation errors, but does not provide packet details, affected version ranges, mitigations, or patch identifiers in the supplied bundle.
Mitigation direction
- Review Cisco’s advisory for affected releases and remediation guidance.
- Prioritize vendor-recommended updates or workarounds for confirmed affected deployments.
- Engage Cisco support if product or release mapping is unclear.
- Monitor Remote PHY paths for unexplained IPv4 traffic disruption.
Validation and detection
- Inventory Cisco Remote PHY deployments and software versions.
- Compare deployed releases against Cisco’s advisory and support guidance.
- Review network monitoring for DoS-like IPv4 disruption through these devices.
- Document whether each deployment is affected, remediated, or not applicable.
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-399: 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-2018-15391 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- 20181003 Cisco Remote PHY IPv4 Fragment 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.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.