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CVE Record

CVE-2021-23784: Cross-site Scripting (XSS)

This affects the package tempura before 0.4.0. If the input to the esc function is of type object (i.e an array) it is returned without being escaped/sanitized, leading to a potential Cross-Site Scripting vulnerability.

MediumCVSS 5.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-23784 is a cross-site scripting issue in the JavaScript package tempura before 0.4.0. When tempura's esc function receives an object, including an array, it can return that value without escaping. In applications that pass user-controlled data there, this may allow script injection into a user's browser.

Executive priority

Treat this as a moderate web application risk. It is not currently supported by the supplied sources as actively exploited, but XSS can affect customer trust, session safety, and content integrity where vulnerable rendering paths exist. Patch during the next normal security maintenance window, faster for internet-facing affected applications.

Technical view

The vulnerability affects tempura versions before 0.4.0. The esc function fails to sanitize object-type input, including arrays, creating potential XSS. CVSS 3.1 is 5.4: network reachable, low complexity, no privileges required, user interaction required, with limited confidentiality and integrity impact.

Likely exposure

Exposure is limited to applications that depend on tempura before 0.4.0 and allow untrusted object or array values to reach esc output. The sources do not identify specific downstream products, hosted services, or default-exposed deployments.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. The CVSS vector indicates exploitation requires user interaction. The temporal metric E:P suggests proof-of-concept maturity, but no cited source here confirms in-the-wild attacks.

Researcher notes

Key unknowns are application-specific: whether tempura is present, whether vulnerable versions are reachable, and whether user-controlled object or array values flow into esc. The supplied sources identify the fixed release but do not enumerate exploit chains, affected downstream applications, or compensating controls.

Mitigation direction

  • Upgrade tempura to version 0.4.0 or later.
  • Review vendor advisory and release notes before deployment.
  • Audit lockfiles for transitive tempura versions below 0.4.0.
  • Normalize or reject untrusted object and array input before escaping.
  • Prioritize externally reachable pages that render user-controlled content.

Validation and detection

  • Check package manifests and lockfiles for tempura versions.
  • Confirm production builds resolve tempura to 0.4.0 or later.
  • Review code paths passing untrusted data to esc.
  • Add regression tests for object and array escaping behavior.
  • Test affected user-facing pages for safe rendering.
Prepared
Confidence
high
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

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CVE-2021-23784 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P

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
4Source 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:N/UI:R/S:U/C:L/I:L/A:N/E:P2.82.5Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.4Medium
CVSS 3.1 vector shape for CVE-2021-23784Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P

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
n/atempuraunspecifiedListed
Weakness

CWE details

No CWE listed

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