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CVE Record

CVE-2021-35240: Stored XSS via Help Server settings

A security researcher stored XSS via a Help Server setting. This affects customers using Internet Explorer, because they do not support 'rel=noopener'.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-35240 is a stored cross-site scripting issue in SolarWinds Orion Platform Help Server settings. Business risk is narrower than many XSS flaws because the CVSS vector requires high privileges, high complexity, adjacent access, and user interaction, with specific concern for Internet Explorer users.

Executive priority

Treat as a moderate-priority remediation item for SolarWinds Orion environments, especially where legacy browsers remain in use. It does not carry confirmed active exploitation in the provided sources, but Orion is a sensitive management platform and should not be left on affected versions.

Technical view

SolarWinds Orion Platform 2020.2.6 and earlier are listed as affected. The issue is CWE-79 stored XSS via Help Server settings, relevant to Internet Explorer because it does not support rel=noopener. CVSS 3.1 is 6.5: AV:A/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L.

Likely exposure

Exposure is most likely in environments still running Orion Platform 2020.2.6 or earlier and where Internet Explorer is used to access Orion. Risk depends on whether privileged users can modify Help Server settings and whether another user interacts with the stored content.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. The CVSS vector indicates constrained exploitation: adjacent access, high complexity, high privileges, and user interaction. Impact is potentially significant for confidentiality but limited for integrity and availability.

Researcher notes

Evidence is limited to the CVE record and SolarWinds references. Do not assume broader product impact beyond Orion Platform 2020.2.6 and previous versions. Validate exposure through version, browser use, and administrative configuration paths rather than attempting weaponized testing.

Mitigation direction

  • Review SolarWinds advisory CVE-2021-35240 and the linked mitigation article.
  • Apply SolarWinds Orion Platform 2020.2.6 Hotfix 1 or vendor-directed successor guidance where applicable.
  • Retire Internet Explorer access to Orion wherever operationally possible.
  • Restrict Help Server setting changes to necessary administrators only.
  • Review SolarWinds secure configuration guidance for Orion Platform.

Validation and detection

  • Inventory Orion Platform versions and flag 2020.2.6 or earlier.
  • Confirm whether Orion users still access the platform through Internet Explorer.
  • Review who can modify Help Server settings in Orion.
  • Check configuration or audit records for unexpected Help Server setting changes.
  • Verify the applicable SolarWinds hotfix or mitigation is applied.
Prepared
Confidence
high
Sources
6

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-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2021-35240 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
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L

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
5Source 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
6.5CVSS 3.1MediumCVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L0.75.3Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2021-35240Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L

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
SolarWindsOrion Platform2020.2.6 and previous versionsListed
Weakness

CWE details

CWE-79

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