Update sql_injection_login.py

[bandarisantosh]

No description provided.

[private-semgrep-app]

Found a template created with string formatting. This is susceptible to server-side template injection and cross-site scripting attacks.

_{Ignore this finding from render-template-string.}

[private-semgrep-app]

Semgrep Assistant suggests the following fix: Use Flask's render_template with an HTML template instead of render_template_string.

View step-by-step instructions

1. Replace the flask.render_template_string(username) call with a safer method to handle the username. If you need to display the username, use the render_template function with a proper HTML template.
2. Create a new HTML template file, for example username_display.html, and include a placeholder for the username: <div>{{ username }}</div>.
3. Replace the flask.render_template_string(username) line with return render_template('username_display.html', username=username).
4. Ensure that the username_display.html file is stored in the appropriate templates directory for Flask to find it.

This code change should be a good starting point:

Suggested change

	flask.render_template_string(username)
	return render_template('username_display.html', username=username)

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[private-semgrep-app]

Detected user input used to manually construct a SQL string. This is usually bad practice because manual construction could accidentally result in a SQL injection. An attacker could use a SQL injection to steal or modify contents of the database. Instead, use a parameterized query which is available by default in most database engines. Alternatively, consider using the Django object-relational mappers (ORM) instead of raw SQL queries.

View Dataflow Graph

flowchart LR
    classDef invis fill:white, stroke: none
    classDef default fill:#e7f5ff, color:#1c7fd6, stroke: none

    subgraph File0["<b>vulns/sql_injection/sql_injection_login.py</b>"]
        direction LR
        %% Source

        subgraph Source
            direction LR

            v0["<a href=https://github.com/bandarisantosh/bad-python-app/blob/b12195a4461a6800b290d02cde200b9c17fbd99b/vulns/sql_injection/sql_injection_login.py#L14 target=_blank style='text-decoration:none; color:#1c7fd6'>[Line: 14] request.form</a>"]
        end
        %% Intermediate

        subgraph Traces0[Traces]
            direction TB

            v2["<a href=https://github.com/bandarisantosh/bad-python-app/blob/b12195a4461a6800b290d02cde200b9c17fbd99b/vulns/sql_injection/sql_injection_login.py#L14 target=_blank style='text-decoration:none; color:#1c7fd6'>[Line: 14] form</a>"]

            v3["<a href=https://github.com/bandarisantosh/bad-python-app/blob/b12195a4461a6800b290d02cde200b9c17fbd99b/vulns/sql_injection/sql_injection_login.py#L16 target=_blank style='text-decoration:none; color:#1c7fd6'>[Line: 16] username</a>"]
        end
            v2 --> v3
        %% Sink

        subgraph Sink
            direction LR

            v1["<a href=https://github.com/bandarisantosh/bad-python-app/blob/b12195a4461a6800b290d02cde200b9c17fbd99b/vulns/sql_injection/sql_injection_login.py#L23 target=_blank style='text-decoration:none; color:#1c7fd6'>[Line: 23] f&quot;SELECT * FROM users WHERE username=&apos;{username}&apos; AND password=&apos;{password_hash}&apos;&quot;</a>"]
        end
    end
    %% Class Assignment
    Source:::invis
    Sink:::invis

    Traces0:::invis
    File0:::invis

    %% Connections

    Source --> Traces0
    Traces0 --> Sink

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_{Ignore this finding from tainted-sql-string.}

[private-semgrep-app]

Semgrep Assistant suggests the following fix: Use parameterized queries instead of format strings to prevent SQL injection.

View step-by-step instructions

1. Replace the format string with a parameterized query. Remove the f prefix from the string and replace the dynamic values with placeholders. For example, change the SQL string to: sql = "SELECT * FROM users WHERE username=%s AND password=%s".
2. Pass the dynamic values as a tuple in the second argument of the execute_read method. For example, update the call to: db_result = app.db_helper.execute_read(sql, (username, password_hash)).

This change uses parameterized queries, which help prevent SQL injection by separating SQL code from data.

This code change should be a good starting point:

Suggested change

	sql = f"SELECT * FROM users WHERE username='{username}' AND password='{password_hash}'"
	sql = "SELECT * FROM users WHERE username=%s AND password=%s"
	db_result = app.db_helper.execute_read(sql, (username, password_hash))

_{Leave feedback with a 👍 / 👎. Save a memory with /remember <your custom instructions>.}