Listen to this Post
The vulnerability CVE-2025-27890 stems from an incomplete authorization check during the synchronization process between linked devices, such as an iPhone and a paired Mac. When a WhatsApp client receives a synchronization message from a linked device, it fails to fully validate if the message originated from a legitimately paired and authorized source. This flaw allows an attacker, who has already obtained a privileged network position (e.g., via a malicious gateway or MITM), to craft and inject a fraudulent synchronization message. This malicious message can contain a specially crafted element that forces the target’s WhatsApp client to automatically fetch and process content from an arbitrary, attacker-controlled URL. This unsanctioned request is made with the privileges of the victim’s WhatsApp application, potentially leading to local data exposure or, as noted, acting as a primer for a more complex chain involving a separate OS-level vulnerability (CVE-2025-43300) to achieve remote code execution.
Platform: WhatsApp iOS/Mac
Version: <2.25.21.73/78
Vulnerability: Incomplete Authorization
Severity: Medium
date: 2025-03-25
Prediction: Patch expected 2025-04-15
What Undercode Say:
`nmap -p 5222,443 –script http- `
`curl -H “X-WA-Linked-Device: spoofed_payload” `
How Exploit:
Craft malicious sync message with embedded URL. Intercept or spoof traffic from a linked device. Send message to target client, triggering automatic URL fetch.
Protection from this CVE:
Update to latest version. Use VPN on untrusted networks.
Impact:
Arbitrary URL processing, data exposure, exploit chain enabler.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: www.cve.org
Extra Source Hub:
Undercode
