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CVE Record

CVE-2021-23413: Denial of Service (DoS)

This affects the package jszip before 3.7.0. Crafting a new zip file with filenames set to Object prototype values (e.g __proto__, toString, etc) results in a returned object with a modified prototype instance.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-23413 affects jszip versions before 3.7.0. A specially crafted ZIP filename can alter object prototype behavior inside the library and may cause denial of service. The business risk is disruption in services that process or create ZIP files from untrusted input.

Executive priority

Prioritize routine patching unless the organization processes untrusted ZIP content at scale or in customer-facing workflows. In those cases, schedule remediation promptly because impact is service availability, not data theft based on current evidence.

Technical view

The issue is a prototype-pollution-style flaw in jszip object handling. Filenames matching Object prototype properties can produce returned objects with modified prototype instances. Published CVSS is 5.3, with network reachability, low attack complexity, no privileges, no user interaction, and low availability impact.

Likely exposure

Exposure is most likely in JavaScript or Java WebJar applications using jszip before 3.7.0, especially where ZIP filenames come from users, uploads, integrations, or generated archives based on external data.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Treat this as a dependency-risk and availability issue, not as confirmed in-the-wild exploitation.

Researcher notes

The source bundle identifies jszip before 3.7.0 and upstream PR/commit references. No CWE is listed in the bundle. Validate reachability by mapping application ZIP creation/parsing flows and checking whether attacker-controlled filenames can reach jszip object handling.

Mitigation direction

  • Upgrade jszip to 3.7.0 or later wherever directly or transitively used.
  • Update affected Java WebJar or npm WebJar packages if present.
  • Regenerate lockfiles after dependency updates and review resolved jszip versions.
  • If immediate upgrade is blocked, check vendor guidance for supported mitigations.

Validation and detection

  • Search dependency manifests and lockfiles for jszip versions below 3.7.0.
  • Run software composition analysis against JavaScript and Java WebJar dependencies.
  • Confirm production builds resolve to jszip 3.7.0 or later.
  • Review ZIP-handling paths that accept filenames from untrusted sources.
Prepared
Confidence
high
Sources
7

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-2021-23413 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
Medium
CVSS
5.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
7Source 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
5.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.3Medium
CVSS 3.1 vector shape for CVE-2021-23413Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
n/ajszipunspecifiedListed
Weakness

CWE details

No CWE listed

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