Security readout for executives and security teams
Plain-English summary
This flaw can crash specific Cisco ASR 1000 routers by exhausting resources through ARP traffic from a nearby network position. The business risk is network service interruption, not data theft or system takeover, based on the provided sources.
Executive priority
Treat as high priority for networks where affected ASR 1000 routers support critical connectivity. The main business impact is outage risk from router reloads, especially where redundancy is weak or adjacent network access is broad.
Technical view
CVE-2020-3508 affects Cisco IOS XE Software on Cisco ASR 1000 Series routers with a 20-Gbps Embedded Services Processor installed. Insufficient error handling after platform limits are reached can let an unauthenticated adjacent attacker trigger resource exhaustion and device reload.
Likely exposure
Exposure is limited to environments running Cisco ASR 1000 Series routers with the 20-Gbps ESP and reachable adjacent network paths. Internet-wide remote exposure is not supported by the provided CVSS vector or description.
Exploitation context
The provided sources describe adjacent, unauthenticated exploitation via crafted IP ARP message sequences causing denial of service. CISA KEV status is false in the bundle, and no cited source here confirms active exploitation.
Researcher notes
The available evidence supports CWE-400 resource exhaustion, CVSS 3.1 score 7.4, adjacent attack vector, low complexity, no privileges, no user interaction, changed scope, and high availability impact. The bundle does not provide fixed version details.
Mitigation direction
- Check Cisco advisory for affected releases, fixed software, and official workarounds.
- Inventory ASR 1000 routers and confirm whether 20-Gbps ESP modules are installed.
- Limit untrusted Layer 2 adjacency to affected router interfaces where operationally possible.
- Prioritize IOS XE remediation during maintenance for exposed routing infrastructure.
- Monitor affected routers for resource exhaustion, ARP anomalies, and unexpected reloads.
Validation and detection
- Identify ASR 1000 devices running Cisco IOS XE in asset inventory.
- Confirm hardware includes the 20-Gbps Embedded Services Processor.
- Map adjacent networks that can send ARP traffic to affected interfaces.
- Review device logs for unexplained reloads or resource exhaustion events.
- Compare installed software against Cisco advisory guidance.
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-2020-3508 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
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/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:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200924 Cisco IOS XE Software for Cisco ASR 1000 Series 20-Gbps Embedded Services Processor IP ARP 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.