Threat: Malicious Image Loading
- Threat: Malicious Image Loading
- Description: Coil is used to load and decode an image from a source controlled by an attacker or a compromised source. The attacker crafts a malicious image that exploits vulnerabilities within image decoding libraries used by Coil (like BitmapFactory or platform decoders). When Coil processes this image, the exploit is triggered.
- Impact: Application crash, denial of service (DoS), potential remote code execution on the user's device, leading to complete compromise of the application and user data.
- Coil Component Affected:
ImageLoader,Fetcher,Decoder, underlying image decoding libraries. - Risk Severity: Critical
- Mitigation Strategies:
- Strictly load images from trusted and highly reputable sources only. Implement robust validation of image URLs and origins.
- Implement comprehensive error handling specifically around image loading and decoding. Ensure graceful failure and prevent application crashes.
- Maintain Coil and all underlying dependencies, especially image decoding libraries, at the latest versions. Regularly update to benefit from critical security patches.
- Consider employing image format validation before processing images to ensure they adhere to expected and safe formats.
- Implement strong input sanitization and validation on any user-provided image URLs or data that influences image loading.
Threat: Cache Poisoning
- Threat: Cache Poisoning
- Description: An attacker successfully injects a malicious image into Coil's cache, replacing a legitimate image. This could be achieved by exploiting weaknesses in cache storage security or through a Man-in-the-Middle attack if initial image loading happens over HTTP (though less directly Coil's fault, the impact is through Coil's cache). When the application subsequently requests the legitimate image, Coil serves the malicious, cached version.
- Impact: Display of malicious or inappropriate content to users, potential for phishing or social engineering attacks by displaying deceptive images, application malfunction if the malicious image is incompatible or triggers unexpected behavior.
- Coil Component Affected:
DiskCache,MemoryCache,ImageLoader(cache retrieval). - Risk Severity: High
- Mitigation Strategies:
- Ensure robust security for cache storage. Protect the disk cache directory with strict file system permissions to prevent unauthorized write access.
- Implement strong cache integrity checks. Utilize checksums or cryptographic signatures to verify the integrity of cached images before serving them.
- Enforce HTTPS for all image loading operations. This significantly reduces the risk of Man-in-the-Middle attacks that could be used to inject malicious content during initial image retrieval and cache population.
- Implement appropriate cache eviction and invalidation policies. Regularly clear or invalidate the cache to limit the window of opportunity for serving poisoned content.
- Consider using signed URLs or other authentication mechanisms for image sources to further verify the legitimacy of the image source and content.