CVE-2022-31009 in wire-ios
Summary
by MITRE • 06/23/2022
wire-ios is an iOS client for the Wire secure messaging application. Invalid accent colors of Wire communication partners may render the iOS Wire Client partially unusable by causing it to crash multiple times on launch. These invalid accent colors can be used by and sent between Wire users. The root cause was an unnecessary assert statement when converting an integer value into the corresponding enum value, causing an exception instead of a fallback to a default value. This issue is fixed in [wire-ios](https://github.com/wireapp/wire-ios/commit/caa0e27dbe51f9edfda8c7a9f017d93b8cfddefb) and in Wire for iOS 3.100. There is no workaround available, but users may use other Wire clients (such as the [web app](https://app.wire.com)) to continue using Wire, or upgrade their client.
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Analysis
by VulDB Data Team • 06/25/2022
The vulnerability CVE-2022-31009 affects the wire-ios mobile application, which serves as the official iOS client for the Wire secure messaging platform. This security flaw represents a critical reliability issue that can severely impact user access to the communication service. The vulnerability stems from improper handling of accent color data within the application's user interface rendering logic, specifically affecting how the client processes color values associated with communication partners. The issue manifests as application instability during the launch process, where repeated crashes occur due to malformed color data being processed by the client software.
The technical root cause of this vulnerability lies in an unnecessary assert statement that occurs during the conversion process from integer values to corresponding enum representations within the application's color handling subsystem. This assertion mechanism fails to gracefully handle invalid input data, instead triggering an exception that causes the application to terminate unexpectedly. According to CWE classification, this represents a weakness in the form of an assertion failure that leads to denial of service conditions, specifically falling under CWE-665 Improper Initialization. The flaw demonstrates poor error handling practices where the application does not implement proper fallback mechanisms when encountering unexpected data formats, instead choosing to crash rather than continue operating with default values.
The operational impact of this vulnerability extends beyond simple application instability to represent a broader threat to user productivity and communication continuity. When users encounter invalid accent colors from other Wire users, the client experiences multiple crashes upon launch, effectively rendering the application partially unusable until the issue is resolved. This creates a cascading effect where legitimate users may be unable to access their communication channels, potentially disrupting business operations or personal communications. The vulnerability can be exploited by any Wire user who sends malformed accent color data to another user, making it a vector for both accidental and intentional disruption of service. From an attack perspective, this issue aligns with ATT&CK technique T1499.004 Network Denial of Service, as it creates a condition where legitimate users cannot access network services due to client-side application crashes.
The fix implemented in wire-ios version 3.100 addresses this issue by removing the problematic assert statement and replacing it with proper error handling that allows the application to gracefully fall back to default color values when invalid data is encountered. This solution demonstrates the importance of defensive programming practices and proper input validation in client-side applications. The absence of a workaround means that affected users must either upgrade to the patched version or utilize alternative client platforms such as the web application to maintain access to Wire services. This vulnerability highlights the critical importance of robust error handling in mobile applications where user data can be manipulated by other users in the system, making proper validation and graceful degradation essential security practices. The incident underscores the need for comprehensive testing of user-generated content handling and the implementation of fail-safe mechanisms that prevent application crashes from affecting core service availability.