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CVE Record

CVE-2021-1466: Cisco SD-WAN vDaemon Buffer Overflow Vulnerability

A vulnerability in the vDaemon service of Cisco SD-WAN vManage Software could allow an authenticated, local attacker to cause a buffer overflow on an affected system, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete bounds checks for data that is provided to the vDaemon service of an affected system. An attacker could exploit this vulnerability by sending malicious data to the vDaemon listening service on the affected system. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could allow the attacker to cause the vDaemon listening service to reload and result in a DoS condition.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

MediumCVSS 5.4Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-1466 can let an authenticated attacker disrupt Cisco SD-WAN Manager/vManage by crashing and reloading the vDaemon service. The business impact is service disruption, not confirmed data theft. Cisco says software updates are available and there are no workarounds.

Executive priority

Treat as a scheduled but meaningful infrastructure fix. It is not described as remotely unauthenticated or actively exploited, but disruption to SD-WAN management can affect operations and incident response visibility.

Technical view

The vDaemon service has incomplete bounds checking, mapped to CWE-20. Malicious data sent to the affected listening service can trigger a buffer overflow, causing vDaemon reload and denial of service. CVSS 3.1 is 5.4 with low complexity and low privileges required.

Likely exposure

Exposure is limited to organizations running affected Cisco Catalyst SD-WAN Manager or Cisco SD-WAN vManage Software versions listed in the advisory. Risk increases where authenticated users can reach the vDaemon listening service.

Exploitation context

The provided sources do not report active exploitation, public exploit use, or KEV listing. The attacker must be authenticated and able to send crafted data to the affected service. Impact is described as DoS with limited integrity and availability effects.

Researcher notes

Key constraints are authenticated access and vDaemon reachability. Sources describe DoS through buffer overflow, not code execution. The record has a 2024 publication date for a 2021 CVE identifier, so rely on Cisco’s advisory for affected and fixed-release details.

Mitigation direction

  • Apply Cisco software updates that address this vulnerability.
  • Use Cisco’s advisory to select the correct fixed release path.
  • Do not rely on workarounds; Cisco states none address this issue.
  • Prioritize systems managing production SD-WAN environments.
  • Monitor vDaemon stability until upgrades are complete.

Validation and detection

  • Inventory Cisco SD-WAN Manager or vManage versions.
  • Compare installed versions against Cisco’s affected release list.
  • Confirm upgraded systems run a Cisco-fixed release.
  • Review operational logs for unexpected vDaemon reloads.
  • Verify management-plane access is limited to authorized users.
Prepared
Confidence
high
Sources
3

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-20: 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
cve · low confidence lookup

CVE-2021-1466 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
Medium
CVSS
5.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/RL:X/RC:X/E:X

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
2Source links

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
5.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/RL:X/RC:X/E:X2.82.5Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.4Medium
CVSS 3.1 vector shape for CVE-2021-1466Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/RL:X/RC:X/E:X

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco Catalyst SD-WAN Manager19.2.1, 18.4.4, 20.1.1.1, 20.1.1, 19.3.0, 19.2.2, 19.2.099, 18.3.6, 18.3.7, 19.2.0, 18.3.8, 19.0.0, 19.1.0, 18.4.302, 18.4.303, 19.2.097, 19.2.098, 17.2.10, 18.3.6.1, 19.0.1a, 18.2.0, 18.4.3, 18.4.1, 17.2.8, 18.3.3.1, 18.4.0, 18.3.1, 17.2.6, 17.2.9, 18.3.4, 17.2.5, 18.3.1.1, 18.3.5, 18.4.0.1, 18.3.3, 17.2.7, 17.2.4, 18.3.0unknown
Weakness

CWE details

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

CWE-20 · source CWE mapping

Improper Input Validation

Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.