# LiteLLM SQL Injection Fix Verification Report

## Fix Summary

The upstream fix for CVE-2026-42271 parameterizes the combined verification-token lookup in `litellm/proxy/utils.py`. Previously, the raw SQL query interpolated the attacker-controlled bearer token directly into the `WHERE` clause (`WHERE v.token = '{token}'`), allowing SQL injection. The patch changes the predicate to a positional parameter (`WHERE v.token = $1`), forwards `hashed_token` as a bound argument, and updates the helper `_query_first_with_cached_plan_fallback()` to pass `*args` through to `self.db.query_first()`. This report verifies that the proposed patch applies cleanly to the vulnerable `litellm==1.83.6` package and that the same real LiteLLM proxy + PostgreSQL environment rejects the previously exploited time-delay payload while still accepting legitimate virtual keys.

## Changes Made

- **File modified:** `litellm/proxy/utils.py`
- **Change 1:** `_query_first_with_cached_plan_fallback()` now accepts `*args` and forwards them to `self.db.query_first()` for both the initial query and the cached-plan retry query.
- **Change 2:** The `combined_view` token lookup changed from `WHERE v.token = '{token}'` to `WHERE v.token = $1`.
- **Change 3:** The call site now passes the `hashed_token` as a bound query argument: `self._query_first_with_cached_plan_fallback(sql_query, hashed_token)`.

The patch is the exact upstream commit `4dc416ee749122ca91e3bca095217478663419e7` (`fix(proxy): use parameterized query for combined_view token lookup`).

## Verification Steps

1. **Prepared a patched copy of the vulnerable package.**
   - Copied `litellm` from the `litellm==1.83.6` virtual environment to `bundle/coding/verify_work/litellm`.
   - Applied `bundle/coding/proposed_fix.diff` with `patch -p1`.

2. **Verified the code transformation.**
   - Confirmed the raw SQL interpolation `WHERE v.token = '{token}'` is removed.
   - Confirmed the parameterized predicate `WHERE v.token = $1` is present.
   - Confirmed `_query_first_with_cached_plan_fallback()` accepts `*args` and passes them to `self.db.query_first()`.
   - Confirmed `hashed_token` is passed as a query argument at the call site.

3. **Ran a live end-to-end test.**
   - Started the cached PostgreSQL instance on `127.0.0.1:36549` with `log_statement = 'all'`.
   - Reused the `litellm_repro_vuln` database and Prisma schema already present in the cache.
   - Started a real LiteLLM proxy with the patched package on `127.0.0.1:36327` using `PYTHONPATH` to override the venv installation.
   - Generated a valid virtual key via `/key/generate` using the master key.
   - Sent the same SQL-injection payload used in the reproduction (`' OR EXISTS(SELECT 1 FROM pg_sleep(3)) --`) as the `Authorization: Bearer` token to `GET /model/info`.
   - Sent the same request with the legitimate virtual key.

## Test Results

Results captured in `bundle/coding/verify_work/verify_result.txt`:

```text
result=passed
injection_time=0.022135
injection_code=401
valid_key_time=0.006282
valid_key_code=200
proxy_port=36327
pg_port=36549
```

The Python verification check produced:

```json
{
  "injection_rejected": true,
  "injection_not_delayed": true,
  "valid_key_accepted": true,
  "pglog_no_injected_sleep": true
}
```

- **Injection request:** returned HTTP 401 with `type: "token_not_found_in_db"` in 0.022 seconds. The previously vulnerable path would have taken ~3 seconds and returned HTTP 200 with model data.
- **Valid key request:** returned HTTP 200 with the expected `{"data":[{"model_name":"gpt-4o", ...}]}` response in 0.006 seconds, proving the parameterized fix does not break normal authentication.
- **PostgreSQL logs:** did not show a vulnerable raw query containing the injected `pg_sleep(3)` expression; the payload was only present as a bound parameter value.

## Remaining Concerns

- The patch fixes the single `combined_view` token lookup sink. The variant analysis confirmed that alternate API-key headers (`API-Key`, `x-litellm-api-key`) reach the same sink and are therefore also covered by this fix. Other raw SQL builders in the proxy were noted in the variant analysis, but they either use constants/configuration values, positional parameters, or were separately hardened in the fixed release (`1.83.7`). A broader security audit of all raw SQL call sites remains good practice.
- The reproduction and verification used Python optimization (`PYTHONOPTIMIZE=1`), which matches the product-mode path where the injection was reachable. Deployments should ensure the fix is applied before re-enabling optimization.
- Recommended hardening: add regression tests that send bearer tokens containing quotes, SQL comments, and time-based expressions to all protected proxy endpoints and assert quick 401 rejection; rotate virtual keys and review PostgreSQL logs for suspicious SQL syntax in bearer-token values.