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CVE Record

CVE-2021-34425: Server Side Request Forgery in Zoom Client for Meetings chat

The Zoom Client for Meetings before version 5.7.3 (for Android, iOS, Linux, macOS, and Windows) contain a server side request forgery vulnerability in the chat\'s "link preview" functionality. In versions prior to 5.7.3, if a user were to enable the chat\'s "link preview" feature, a malicious actor could trick the user into potentially sending arbitrary HTTP GET requests to URLs that the actor cannot reach directly.

MediumCVSS 4.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Older Zoom clients could be abused through chat link previews to make a victim's device send HTTP GET requests to locations the attacker could not directly access. This requires the user to have link preview enabled and be tricked into interacting with malicious chat content. The issue is fixed by moving Zoom Client for Meetings to version 5.7.3 or later.

Executive priority

Treat this as a medium-priority endpoint hygiene issue, not an emergency. The business risk is reduced by required user interaction and lack of sourced active exploitation, but broad Zoom deployment can create avoidable exposure if old clients remain in use.

Technical view

CVE-2021-34425 is an SSRF flaw in Zoom Client for Meetings chat link preview functionality before 5.7.3 across Android, iOS, Linux, macOS, and Windows. The CVSS 3.1 score is 4.7 with network attack vector, high complexity, no privileges, required user interaction, changed scope, and limited confidentiality and integrity impact.

Likely exposure

Exposure is most likely on endpoints running Zoom Client for Meetings earlier than 5.7.3 where chat link previews are enabled. The source bundle lists affected platforms broadly, but does not provide narrower vulnerable build ranges beyond versions before 5.7.3.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires user interaction and link preview being enabled. A malicious actor could induce arbitrary HTTP GET requests to otherwise unreachable URLs, but the public bundle does not describe broader compromise or availability impact.

Researcher notes

The key validation point is version and feature state: Zoom Client for Meetings before 5.7.3 plus enabled chat link preview. The bundle does not provide exploit telemetry, detailed affected build numbers, or named compensating controls beyond the fixed version and vendor bulletin reference.

Mitigation direction

  • Upgrade Zoom Client for Meetings to version 5.7.3 or later.
  • Check Zoom's security bulletin for current vendor guidance.
  • Where upgrades are delayed, disable chat link previews if policy allows.
  • Prioritize managed endpoints with older Zoom clients installed.

Validation and detection

  • Inventory Zoom Client for Meetings versions across all endpoint platforms.
  • Confirm no managed device runs a version earlier than 5.7.3.
  • Review whether chat link preview is enabled in client or account policy.
  • Check unmanaged or BYOD devices that join corporate Zoom meetings.
  • Document remaining exceptions and compensating controls.
Prepared
Confidence
medium
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

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CVE-2021-34425 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.7 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/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.

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
4.7CVSS 3.1MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N1.62.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.7Medium
CVSS 3.1 vector shape for CVE-2021-34425Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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
Zoom Video Communications IncZoom Client for Meetings for AndroidunspecifiedListed
Zoom Video Communications IncZoom Client for Meetings for iOSunspecifiedListed
Zoom Video Communications IncZoom Client for Meetings for LinuxunspecifiedListed
Zoom Video Communications IncZoom Client for Meetings for macOSunspecifiedListed
Zoom Video Communications IncZoom Client for Meetings for WindowsunspecifiedListed
Weakness

CWE details

No CWE listed

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