CVE-2025-71063 in Errands
Summary
by MITRE • 01/12/2026
Errands before 46.2.10 does not verify TLS certificates for CalDAV servers.
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Analysis
by VulDB Data Team • 02/05/2026
The vulnerability identified as CVE-2025-71063 affects the Errands application version 46.2.10 and earlier, specifically concerning its handling of TLS certificates when establishing connections to CalDAV servers. This represents a critical security flaw in the application's cryptographic verification mechanisms that could potentially allow adversaries to compromise the integrity of calendar data exchanges between client and server components. The issue stems from the application's failure to properly validate SSL/TLS certificates during the connection establishment process, creating a potential attack vector for man-in-the-middle scenarios where malicious actors could intercept or manipulate calendar synchronization communications.
The technical flaw manifests as a missing certificate validation step within the application's network communication stack when connecting to CalDAV servers. This vulnerability directly maps to CWE-295, which addresses improper certificate validation in secure communications, and aligns with ATT&CK technique T1566.002 for credential access through phishing attacks that could exploit the weakened TLS security posture. The application's failure to verify certificate authenticity means that it will accept connections to servers with invalid, expired, or self-signed certificates without proper warning or rejection, potentially allowing attackers to establish fraudulent connections that appear legitimate to the client application.
The operational impact of this vulnerability extends beyond simple data integrity concerns to encompass potential data exfiltration, calendar manipulation, and unauthorized access to sensitive personal or organizational information. When users synchronize their calendar data with CalDAV servers, they expect that their communications remain private and authentic, but this vulnerability undermines that trust by enabling attackers to impersonate legitimate servers. The implications are particularly severe for organizations relying on calendar synchronization for scheduling, meeting coordination, and time management, as compromised calendar data could lead to significant operational disruptions, security breaches, or unauthorized access to sensitive scheduling information. Additionally, the vulnerability affects both personal and enterprise users who may unknowingly expose their calendar data to interception or manipulation.
Mitigation strategies for CVE-2025-71063 should prioritize immediate application updates to versions that properly implement TLS certificate validation. System administrators should also implement network-level monitoring to detect unusual CalDAV traffic patterns that might indicate certificate validation bypass attempts. Organizations should consider deploying network segmentation measures to limit access to CalDAV servers and implement additional authentication layers beyond the basic TLS certificate verification. The remediation process should include comprehensive testing of certificate validation procedures and regular security audits of calendar synchronization configurations. Security teams should also establish incident response procedures specifically addressing potential calendar data compromise scenarios, ensuring that users are promptly notified of any security events that might affect their calendar synchronization activities. The vulnerability underscores the critical importance of maintaining proper cryptographic security practices in client applications that handle sensitive personal information through network communications.