This detailed examination, conducted on March 14, 2025, explores CVE-2025-1094, a hypothetical high-severity SQL injection vulnerability in PostgreSQL, based on the provided emulation setup and proof-of-concept (PoC) execution. The analysis covers the vulnerability's introduction, root cause, file contributions, PoC steps, and mitigations, incorporating all intricate details from the emulation process.
CVE-2025-1094 is described as a critical SQL injection flaw in PostgreSQL, affecting versions prior to 17.3, 16.7, 15.11, 14.16, and 13.19, with a CVSS 3.1 base score of 8.1, indicating significant impacts on confidentiality, integrity, and availability. It enables attackers to access sensitive data or execute remote code (RCE), and has been exploited in real-world breaches, such as the BeyondTrust incident affecting 17 enterprise customers, reported on BleepingComputer, and the U.S. Treasury Department breach, detailed on The Register. The emulation, conducted on March 14, 2025, used a Docker setup with server_encoding=EUC_TW and client_encoding=BIG5, crucial for triggering the exploit. The PoC involved injecting a DO block to create a large object, read /etc/passwd via pg_read_file, write it to the large object with lo_put, and export it to /tmp/payload using lo_export, confirming the encoding mismatch's role in enabling unauthorized file access.
The root cause is classified under CWE-149: Improper Neutralization of Quoting Syntax, involving improper handling in PostgreSQL's libpq functions—PQescapeLiteral(), PQescapeIdentifier(), PQescapeString(), and PQescapeStringConn()—which fail to neutralize quoting syntax when results are used to construct input for the psql command-line tool. This is exacerbated when client_encoding is set to BIG5 and server_encoding is EUC_TW, as seen in our setup, allowing SQL injection. The emulation required EUC_TW and zh_TW.EUC_TW to create the mismatch, with issues like psycopg2's lack of EUC_TW support resolved by connecting with UTF8 then switching to BIG5. The exploit's success hinged on executing raw SQL via subprocess.run(["psql", ...]), bypassing safe query handling, as detailed in the logs.
Each file in the setup plays a critical role in emulating CVE-2025-1094. Below is a detailed breakdown in tabular form:
The PoC, executed on March 14, 2025, demonstrates the exploit's impact through the following steps, each with a detailed explanation:
sudo docker compose up --build
db and app), creating containers with updated images if needed, and links them in the postgre_default network. Ensures the vulnerable environment is set up, with db using EUC_TW encoding and app exposing /vuln-endpoint on port 5000, crucial for the exploit's encoding mismatch and endpoint access.curl -X POST http://localhost:5000/vuln-endpoint -d "input=test"
input=test, verifying connectivity and basic functionality, expecting "Executed". Confirms the app is running and can connect to the database, ensuring the setup is ready for the exploit.
python3 cve-2025-1094-exploit.py
Demonstration Video on Vimeo
Click to view the demonstration of the PoC on Vimeo.
To mitigate CVE-2025-1094, the following measures are recommended, based on the emulation insights and industry guidance:
psql to trusted users only, reducing the attack surface.| File | What It Does | Contribution to PoC | Why It’s Needed |
|---|
exploit.py | Sends a POST request with a DO block to create and export a large object, reading /etc/passwd. | Triggers SQL injection, exploits encoding mismatch to execute arbitrary SQL commands. | Enables exploit execution, critical for PoC impact. |
app.py | Flask app exposing /vuln-endpoint, executes raw SQL via psql. | Provides vulnerable endpoint for exploit. | Entry point for exploit, necessary for vulnerability demonstration. |
init.sql | Creates test table with id VARCHAR(255) for string inputs. | Sets up schema for injection, ensures payload execution without type errors. | Database setup for exploit, essential for SQL injection. |
Dockerfile | Builds Flask app container with necessary dependencies. | Creates isolated app service for endpoint deployment. | Deploys vulnerable app, critical for PoC reproducibility. |
docker-compose.yml | Defines and links db and app services with specific configurations. | Orchestrates setup, ensures encoding mismatch and service dependencies. | Links services, essential for environment setup and isolation. |
Dockerfile.db | Builds PostgreSQL container with EUC_TW encoding. | Creates vulnerable database with required encoding. | Sets up database with required encoding, critical for vulnerability trigger. |
/etc/passwd to it, and export to /tmp/payload, printing execution status. Triggers the SQL injection, exploiting the vulnerability to read /etc/passwd, critical for demonstrating CVE-2025-1094's impact, as seen in logs with successful file export.
sudo docker ps
postgre-app-1 and postgre-db-1 are up. Confirms the setup before running the exploit, ensuring both services are active, critical for PoC reliability. Provides the user with the container ID, needed in subsequent commands.sudo docker exec -it bash -c "LC_ALL=C ls -l /tmp/payload && LC_ALL=C cat /tmp/payload"
postgre-db-1 container, listing and displaying /tmp/payload with English output, verifying the exploit's result (should show /etc/passwd). Confirms the exploit worked by checking the file, ensuring /tmp/payload contains sensitive data, aligning with PoC verification, and avoiding locale garbling with LC_ALL=C.
sudo docker exec -it psql -U postgres -d postgres -c "SELECT * FROM test;"
test table, verifying the INSERT from the exploit (should show "Exploit ran with loid ..."). Confirms the exploit's database modification, ensuring the DO block executed, aligning with PoC verification, and validating the loid logging.sudo docker compose down