Ollama 0.11.5-rc0 through current version 0.13.5 contain a null pointer dereference vulnerability in the multi-modal model image processing functionality. When processing base64-encoded image data via the /api/chat endpoint, the application fails to validate that the decoded data represents valid media before passing it to the mtmd_helper_bitmap_init_from_buf function. This function can return NULL for malformed input, but the code does not check this return value before dereferencing the pointer in subsequent operations. A remote attacker can exploit this by sending specially crafted base64 image data that decodes to invalid media, causing a segmentation fault and crashing the runner process. This results in a denial of service condition where the model becomes unavailable to all users until the service is restarted.
Weakness
Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ollama | Ollama | 0.11.6 (including) | 0.13.5 (including) |
| Ollama | Ollama | 0.11.5 (including) | 0.11.5 (including) |
| Ollama | Ollama | 0.11.5-rc0 (including) | 0.11.5-rc0 (including) |
| Ollama | Ollama | 0.11.5-rc1 (including) | 0.11.5-rc1 (including) |
| Ollama | Ollama | 0.11.5-rc2 (including) | 0.11.5-rc2 (including) |
| Ollama | Ollama | 0.11.5-rc3 (including) | 0.11.5-rc3 (including) |
| Ollama | Ollama | 0.11.5-rc4 (including) | 0.11.5-rc4 (including) |
| Ollama | Ollama | 0.11.5-rc5 (including) | 0.11.5-rc5 (including) |
Extended Description
Programmers typically catch NullPointerException under three circumstances:
Of these three circumstances, only the last is acceptable.