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WhatsappApplication

CVE-2018-20655

CRITICAL · 9.8 CVSS v3.1 Published 2019-06-14
Fix available
A fix is available. Upgrade to 2.18.90.24 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
When receiving calls using WhatsApp for iOS, a missing size check when parsing a sender-provided packet allowed for a stack-based overflow. This issue affects WhatsApp for iOS prior to v2.18.90.24 and WhatsApp Business for iOS prior to v2.18.90.24.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack-based buffer overflow vulnerability in WhatsApp for iOS allows remote code execution via specially crafted call packets. The lack of a size check during parsing of sender-provided packets enables attackers to overflow a stack buffer by sending oversized data, potentially leading to arbitrary code execution on the victim's device.

MitigationOrganizations should ensure all iOS devices running WhatsApp or WhatsApp Business are updated to version 2.18.90.24 or later. Since this is a client-side vulnerability requiring a software update from the vendor, users cannot implement traditional remediation—enforcement of updated versions via MDM or security policies is the primary control.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
WhatsappApplication
Affected:< 2.18.90.24
Whatsapp BusinessApplication
Affected:< 2.18.90.24

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if WhatsApp or WhatsApp Business is installed on iOS
    On the iOS device, go to Settings > General > iPhone Storage, or look for the WhatsApp app icon on the home screen to confirm presence of either WhatsApp or WhatsApp Business.
    Affected if Either WhatsApp or WhatsApp Business is installed on the device.
  2. Determine the installed WhatsApp version
    Open WhatsApp on the iOS device, go to Settings > Help > App Info. The version number is displayed next to the app name (e.g., 'WhatsApp 2.18.80').
    Affected if A version is displayed.
  3. Determine the installed WhatsApp Business version
    Open WhatsApp Business on the iOS device, go to Settings > Help > App Info. The version number is displayed next to the app name (e.g., 'WhatsApp Business 2.18.80').
    Affected if A version is displayed.
  4. Compare version against the vulnerable range
    For each installed app (WhatsApp or WhatsApp Business), compare the numeric version to 2.18.90.24. Versions are compared as numeric values where 2.18.90.24 is greater than 2.18.80, 2.18.50, etc.
    Affected if The installed version is less than 2.18.90.24 (for example, 2.18.80, 2.18.50, or any version starting with 2.18.x where x is below 90).

A user is affected if WhatsApp or WhatsApp Business for iOS is installed with a version number lower than 2.18.90.24.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.18.90.24 or later
Fixed in 2.18.90.24
Interim mitigation

Organizations should ensure all iOS devices running WhatsApp or WhatsApp Business are updated to version 2.18.90.24 or later. Since this is a client-side vulnerability requiring a software update from the vendor, users cannot implement traditional remediation—enforcement of updated versions via MDM or security policies is the primary control.

Recommended fix High confidence

WhatsApp for iOS v2.18.90.24 or later, WhatsApp Business for iOS v2.18.90.24 or later

  1. Open the App Store on the iOS device
  2. Search for "WhatsApp" or "WhatsApp Business" depending on which application is installed
  3. Tap the Update button next to the application
  4. Alternatively, enable automatic app updates by going to Settings > App Store > Automatic Downloads and enabling Updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Whatsapp Scoped from the published advisory
  • Consultation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
3.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-20655 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data