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CVE Record

CVE-2020-26071: Cisco SD-WAN vEdge Arbitrary File Creation Vulnerability

A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to create or overwrite arbitrary files on an affected device, which could result in a denial of service (DoS) condition. The vulnerability is due to insufficient input validation for specific commands. An attacker could exploit this vulnerability by including crafted arguments to those specific commands. A successful exploit could allow the attacker to create or overwrite arbitrary files on the affected device, which could result in a DoS condition.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

HighCVSS 8.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

An authenticated local user on affected Cisco SD-WAN software could abuse specific CLI commands to create or overwrite files. That can disrupt device availability and integrity, potentially causing a denial of service. This is not a remote unauthenticated issue, but it matters for environments where CLI access is broadly delegated.

Executive priority

Treat as high priority for Cisco SD-WAN estates, especially devices supporting critical network connectivity. It is not described as remotely exploitable without authentication, but a compromised or overprivileged local account could damage device availability. Patch according to Cisco guidance because no workaround is provided.

Technical view

CVE-2020-26071 is an insufficient input validation issue in Cisco SD-WAN Software CLI commands, mapped to CWE-22. With local access and low privileges, an attacker could pass crafted arguments that create or overwrite arbitrary files, affecting integrity and availability. CVSS 3.1 is 8.4 with local attack vector, scope changed, and no confidentiality impact.

Likely exposure

Exposure is limited to affected Cisco SD-WAN products and versions listed in the source bundle, including Catalyst SD-WAN Manager, SD-WAN vContainer, vEdge Cloud, and vEdge Router. The attacker needs authenticated local CLI access, so risk is highest where device shell or operational access is shared, weakly governed, or compromised.

Exploitation context

The supplied sources do not show active exploitation, and KEV is false. Exploitation requires authenticated local access and crafted CLI arguments to specific commands. The main stated impact is arbitrary file creation or overwrite leading to denial of service.

Researcher notes

Key constraints are local attack vector, low privileges, no user interaction, and integrity and availability impact. The source bundle does not name exploit availability or fixed version numbers beyond Cisco's statement that updates exist. Validate against Cisco's advisory rather than extrapolating unsupported affected or fixed releases.

Mitigation direction

  • Upgrade affected Cisco SD-WAN software using Cisco's advisory guidance.
  • Do not rely on workarounds; Cisco states none address this vulnerability.
  • Restrict CLI access to trusted administrators until patched.
  • Review privileged and low-privilege local accounts on affected devices.
  • Prioritize patching devices supporting critical WAN or branch connectivity.

Validation and detection

  • Inventory Cisco SD-WAN product names and software versions.
  • Compare installed versions with the affected version list and Cisco advisory.
  • Confirm whether local CLI access is available to non-administrators.
  • Review change records for Cisco SD-WAN software updates addressing this CVE.
  • Check device health and logs for unexplained file changes or DoS symptoms.
Prepared
Confidence
high
Sources
3

Public sources used

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 · medium confidence lookup

CWE-22: File access and web shell behavior lookup

File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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.

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description · low confidence lookup

File access behavior lookup

The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2020-26071 mapping review

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

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H/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
8.4CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H/RL:X/RC:X/E:X25.8Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

8.4High
CVSS 3.1 vector shape for CVE-2020-26071Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H/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 Manager20.1.12, 19.2.1, 18.4.4, 18.4.5, 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, 18.3.0, 19.2.3, 18.4.501_ESunknown
CiscoCisco SD-WAN vContainer18.4.5, 20.1.12, 18.3.6, 19.2.1, 19.3.0, 20.1.1, 19.2.2, 18.3.8, 18.4.3, 18.4.4, 18.4.302, 19.1.0, 18.4.303, 19.2.0, 19.2.098, 17.2.10, 18.3.7, 18.3.1, 19.2.099, 19.2.097, 18.3.4, 18.2.0, 18.3.5, 18.4.1, 17.2.5, 17.2.7, 17.2.8, 17.2.9, 18.4.0, 17.2.6, 18.3.0, 17.2.4, 18.3.3, 19.2.3unknown
CiscoCisco SD-WAN vEdge Cloud19.2.1, 20.1.12, 18.4.4, 19.3.0, 18.3.8, 19.2.2, 20.1.1, 18.3.6, 18.4.3, 18.4.302, 18.4.5, 18.4.303, 19.2.098, 19.1.0, 17.2.10, 19.0.1a, 19.2.099, 18.3.7, 19.2.097, 18.3.1, 19.2.0, 17.2.9, 18.3.4, 18.2.0, 18.4.1, 17.2.5, 18.4.0, 18.3.5, 18.3.3, 17.2.7, 17.2.6, 17.2.8, 18.3.0, 17.2.4, 19.2.3unknown
CiscoCisco SD-WAN vEdge Router18.4.303, 18.3.7, 19.3.0, 18.2.0, 20.1.12, 19.2.099, 17.2.10, 18.3.3, 18.3.6, 19.0.0, 17.2.6, 18.4.0, 19.1.01, 19.2.098, 18.3.1, 18.4.302, 19.2.2, 18.3.5, 17.2.9, 19.1.0, 20.1.11, 19.2.097, 18.4.5, 17.2.5, 17.2.8, 18.3.8, 18.3.0, 18.4.3, 18.4.4, 19.2.1, 17.2.4, 18.3.4, 19.0.1a, 20.1.1, 17.2.7, 18.4.1, 19.2.0, 19.2.3unknown
Weakness

CWE details

CWE-22

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

CWE-22 · source CWE mapping

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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