Hypequery is a TypeScript semantic layer for ClickHouse. Prior to 2.5.1, escapeValue() in packages/clickhouse/src/core/utils.ts did not escape backslashes before single quotes during parameter substitution, allowing attacker controlled query parameters with a trailing backslash to escape the closing quote and inject arbitrary SQL. This issue is fixed in version 2.0.2. Version 2.0.2 fixes string parameters, while version 2.5.1 fixes all known vectors. Upgrading to 2.5.1 or later is the only complete fix. In versions 2.0.2 through 2.5.0, serializing non-scalar parameters with  JSON.stringify()  before passing them is a workaround for the object/array vector only.

Affected: npm: @hypequery/clickhouse

A SQL injection vulnerability exists in the `escapeValue()` function used for parameter substitution. `escapeValue()` dispatches on the type of the parameter value, and two of its branches failed to escape safely. An attacker who can control a parameter value can terminate the enclosing string literal and have the rest of the value parsed as SQL.

**Vector 1 - string parameters. Fixed in 2.0.2.** The string branch escaped `'` as `''` but left `\\` untouched. ClickHouse honours C-style backslash escapes as well as SQL-standard quote doubling, so a value ending in an odd number of backslashes escapes the closing quote and the next parameter lands outside the literal:

``` where('a', 'eq', 'x\\') -> WHERE a = 'x\\' AND b = ' OR 1=1 --' ```

**Vector 2 - object and array parameters. Fixed in 2.5.1, NOT in 2.0.2.** The final branch of the same function rendered non-scalar values as `` `'${JSON.stringify(value)}'` `` with no escaping at all. JSON has no reason to escape the apostrophe, so any nested string containing `'` terminates the literal:

``` where('meta', 'eq', { k: \"x' OR 1=1 -- \" }) -> WHERE meta = '{\"k\":\"x' OR 1=1 -- \"}' ```

The 2.0.2 patch changed only the string branch and did not address this. Vector 2 remained exploitable in **2.0.2, 2.1.0, 2.1.1, 2.1.2, 2.1.3, 2.2.0, 2.3.0, 2.4.0 and 2.5.0** - every release this advisory previously reported as patched.

**Who is impacted.** Any application on a version below 2.5.1…