CVE-2024-32655: Npgsql Vulnerable to SQL Injection via Protocol Message Size Overflow

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-14 · updated 2026-06-17
Weakness: CWE-89

Description

Npgsql is the .NET data provider for PostgreSQL. The `WriteBind()` method in `src/Npgsql/Internal/NpgsqlConnector.FrontendMessages.cs` uses `int` variables to store the message length and the sum of parameter lengths. Both variables overflow when the sum of parameter lengths becomes too large. This causes Npgsql to write a message size that is too small when constructing a Postgres protocol message to send it over the network to the database. When parsing the message, the database will only read a small number of bytes and treat any following bytes as new messages while they belong to the old message. Attackers can abuse this to inject arbitrary Postgres protocol messages into the connection, leading to the execution of arbitrary SQL statements on the application's behalf. This vulnerability is fixed in 4.0.14, 4.1.13, 5.0.18, 6.0.11, 7.0.7, and 8.0.3.

Affected products

npgsql: from 4.0.0 before 4.0.14; from 4.1.0 before 4.1.13; from 5.0.0 before 5.0.18; from 6.0.0 before 6.0.11; from 7.0.0 before 8.0.3; from 8.0.0 before 8.0.3 — fixed in 4.0.14, 4.1.13, 5.0.18, 6.0.11, 8.0.3

How to fix

Upgrade to a fixed version: npgsql 4.0.14, 4.1.13, 5.0.18, 6.0.11. Check the vendor advisory for mitigations.

References

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