LiveActive security incident?Get immediate response
CVE Record

CVE-2020-3118: Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability

A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

HighCVSS 8.8Known exploitedUpdated
Glexia's TakeAutomated analysis

Security readout for executives and security teams

CVE-2020-3118 can let a nearby attacker take control of or crash affected Cisco IOS XR devices using Cisco Discovery Protocol traffic. The attacker does not need credentials, but must be on the same Layer 2 broadcast domain. CISA KEV lists this CVE, so treat it as known exploited. Exposure is most likely on Cisco IOS XR routers or devices with Cisco Discovery Protocol enabled on interfaces reachable from the same Layer 2 segment. User-accessible, partner, lab, or unmanaged switching domains increase practical risk. Prioritize this for network infrastructure because successful exploitation could mean router takeover or outage. The Layer 2 adjacency requirement limits internet-scale exposure, but KEV status means affected environments should not defer remediation. Mitigation focus: Review Cisco’s advisory for affected and fixed IOS XR releases.; Prioritize remediation for IOS XR devices on shared Layer 2 networks.; Apply Cisco-recommended software updates or mitigations..

Prepared

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

CWE-134: 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 lookup
description · low confidence lookup

Execution 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 lookup
cve · low confidence lookup

CVE-2020-3118 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.0)
Known Exploited
Yes
Published

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CISA KEV status

Status
Known exploited
Source
CISA / ADP
Date added
Not provided

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
8.8CVSS 3.0HighCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

8.8High
CVSS 3.0 vector shape for CVE-2020-3118Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco IOS XR SoftwareunspecifiedListed
Weakness

CWE details

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-134 · source CWE mapping

Use of Externally-Controlled Format String

Use of Externally-Controlled Format String represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.