Meta Platforms WhatsApp Incorrect Authorization Vulnerability
Meta Platforms · WhatsApp
The flaw is an incorrect authorization issue in the linked device synchronization messaging of Meta Platforms' WhatsApp, affecting WhatsApp for iOS, WhatsApp Business for iOS, and WhatsApp for Mac. An attacker with a network-reachable path and low-privilege access can exploit it without user interaction, since the incomplete authorization check lets an unrelated user cause the target's device to process content fetched from an arbitrary URL, which would partially compromise confidentiality and integrity.
Incomplete authorization of linked device synchronization messages in WhatsApp for iOS prior to v2.25.21.73, WhatsApp Business for iOS v2.25.21.78, and WhatsApp for Mac v2.25.21.78 could have allowed an unrelated user to trigger processing of content from an arbitrary URL on a target’s device. We assess that this vulnerability, in combination with an OS-level vulnerability on Apple platforms (CVE-2025-43300), may have been exploited in a sophisticated attack against specific targeted users.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 2/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 9 days before it was disclosed. Public exploit code (PoC-in-GitHub) appeared 8 months after disclosure.
- First seen exploitedVulnCheck KEV evidence9 days before
- Disclosedday 0
- Added to CISA KEVEU database agrees+4 days
- Public exploit codePoC-in-GitHub+8 mo
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 2 cited passages 2Initial AccessTA0001
Remote unrelated user exploits app via crafted sync messages
could have allowed an unrelated user to trigger processing of content from an arbitrary URL on a target’s device
Command and ControlTA0011
Arbitrary URL content fetched onto the device
trigger processing of content from an arbitrary URL on a target’s device
Detection
0 rules for this CVE · 236 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2025-55177 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploit Public-Facing ApplicationT1190149 general rules
- Arcadyan Router Exploitationscriticaltest
- Citrix ADS Exploitation CVE-2020-8193 CVE-2020-8195criticaltest
- Citrix Netscaler Attack CVE-2019-19781criticaltest
- Confluence Exploitation CVE-2019-3398criticaltest
- CVE-2010-5278 Exploitation Attemptcriticaltest
- CVE-2020-0688 Exchange Exploitation via Web Logcriticaltest
- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
Ingress Tool TransferT110587 general rules
- Greenbug Espionage Group Indicatorscriticaltest
- Pandemic Registry Keycriticaltest
- Curl Download And Execute Combinationhightest
- File Download And Execution Via IEExec.EXEhightest
- File Download From IP Based URL Via CertOC.EXEhightest
- File Download Using Notepad++ GUP Utilityhightest
- File Download Via Bitsadmin To A Suspicious Target Folderhightest
- File Download Via Windows Defender MpCmpRun.EXEhightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- 44 more on OTX