Background exploitation KEV catalog

CVE-2025-55177

Meta Platforms WhatsApp Incorrect Authorization Vulnerability

CheckOps priority index

4.4/10 Patch within 7 days

Severity5.4

Probability1.4

Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 13.5% +0.4 pts in 7 days

CVSS 3.1 5.4 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:

Exploited for 428 days 02 Sept 2025

CISA due date 23 Sept 2025 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

KEV catalog (CISA)02 Sept 2025
Exploited in EUVD (ENISA)02 Sept 2025
Used by ransomwareno
EPSS above 10 %13.5%
No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.

Affected products

WhatsApp Desktop for MacWhatsApp for iOSWhatsApp Business for iOSWhatsApp

Affected versions

2.22.25.2 <2.25.21.78
2.22.25.2 <2.25.21.73

Weaknesses (CWE)

CWE-863

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

29 Aug 2025
Published
02 Sept 2025
Exploitation reported (ENISA)
02 Sept 2025
Added to the KEV catalog
23 Sept 2025
CISA remediation due date
29 Oct 2026
EPSS peak: 13.5%

References

Other exploited vulnerabilities from the same vendor

CVE-2019-18426WhatsApp Cross-Site Scripting Vulnerability
7.7 · Background exploitation
CVE-2019-3568WhatsApp VOIP Stack Buffer Overflow Vulnerability
7.2 · Background exploitation