LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47931: Exponent CMS 2.6 Multiple Vulnerabilities Stored XSS Authentication

Exponent CMS 2.6 contains a stored cross-site scripting vulnerability that allows authenticated attackers to inject malicious scripts through the Title and Text Block parameters in the text editing endpoint. Attackers can inject iframe payloads with embedded SVG onload events to execute arbitrary JavaScript, and the application also exposes database credentials in responses and lacks brute-force protection on authentication endpoints.

MediumCVSS 6.4Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Exponent CMS 2.6 is reported to let logged-in attackers store malicious script content in editable page fields. That can turn normal content pages into a browser-side attack against later viewers. The source bundle also reports database credential exposure and weak authentication controls, but does not name a vendor patch or active exploitation.

Executive priority

Treat this as a moderate-priority web application risk, elevated if Exponent CMS is internet-facing or has many editor accounts. Prioritize inventory, access restriction, and vendor guidance review before broader remediation planning.

Technical view

The CVE describes authenticated stored XSS through Title and Text Block parameters in a text editing endpoint, mapped to CWE-79. CVSS 3.1 is 6.4 with low complexity, low privileges, no user interaction, changed scope, and low confidentiality and integrity impact. Additional reported issues include database credentials in responses and missing brute-force protection.

Likely exposure

Exposure is most likely in internet-facing or intranet Exponent CMS 2.6 deployments where untrusted or lower-privileged users can authenticate and edit text content. The affected version data in the bundle is inconsistent, so asset confirmation should rely on product/version inventory rather than CPE matching alone.

Exploitation context

A public ExploitDB reference is listed, supporting public exploit availability. KEV is false, and the provided sources do not state active exploitation in the wild. The vulnerability requires authenticated access, but compromise of a low-privilege content editor account could be enough to create stored browser-side impact.

Researcher notes

The bundle gives clear stored XSS mechanics and CVSS data, but affected version metadata is weak and no patch status is included. Public exploit availability is evidenced by ExploitDB, while active exploitation is not evidenced. Validate in a controlled environment without publishing payload details.

Mitigation direction

  • Check Exponent CMS and VulnCheck guidance for supported upgrade or patch status.
  • Restrict CMS editing and administration access to trusted users and networks.
  • Audit CMS roles and remove unnecessary text-editing permissions.
  • Review responses for database credential exposure; rotate credentials if exposure is confirmed.
  • Add edge rate limiting or MFA for authentication endpoints where feasible.

Validation and detection

  • Inventory all Exponent CMS instances and confirm whether version 2.6 is present.
  • Review exposed routes for public access to CMS login and editing functions.
  • Check whether non-administrative authenticated users can edit Title or Text Block fields.
  • Inspect recent CMS content changes for unexpected scripts, iframes, or SVG-based markup.
  • Review application logs for repeated login attempts and suspicious editor activity.
Prepared
Confidence
medium
Sources
5

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
description · low confidence lookup

Database behavior lookup

The CVE wording references database injection or access, so collection and exfiltration review may help. 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-2021-47931 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
6.4 (3.1)
Known Exploited
No
Published

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

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.

2CVSS vectors
3Timeline events
1ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

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
6.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N3.12.7VulnCheck
5.1CVSS 4.0MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N——VulnCheck

Vulnerability scoring details

Base CVSS 4.0 score

5.1Medium
CVSS 4.0 vector shape for CVE-2021-47931Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
ExponentcmsExponent CMS0Listed
Weakness

CWE details

CWE-79

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

CWE-79 · source CWE mapping

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs