Pgbouncer
CVE-2021-3935
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Parameterized queries, prepared statements
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Persistence The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 8.1 (HIGH). Attack characteristics: network attack vector, high complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could execute arbitrary SQL commands against the database by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL queries when a connection is first established, despite the use of TLS certificate. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use parameterized queries/prepared statements. Never concatenate user input into SQL. Apply least-privilege database permissions.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as SQL Injection (CWE-89), which allows attackers to execute arbitrary SQL commands against the database. When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL queries when a connection is first established, despite the use of TLS certificate verification and encryption. This flaw affects PgBouncer versions prior to 1.16.1. Affected products include: Pgbouncer, Redhat Enterprise Linux, Fedoraproject Fedora, Debian Debian Linux. Version information: prior to 1.16.1..
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL queries when a connection is first established, despite the use of TLS certificate verification and encryption. This flaw affects PgBouncer versions prior to 1.16.1.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
SQL injection exploits the way applications construct database queries by mixing user input directly into SQL statements.
Affected Products (CPE)NVD
PgBouncer before 1.5.5 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) by send
Stack-based buffer overflow in PgBouncer before 1.25.2 lets a malicious or impersonated PostgreSQL backend corrupt the p
A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Se
Authentication bypass in PgBouncer 1.17.0 through 1.26.0 allows an authenticated attacker who knows a valid password for
PgBouncer 1.6.x before 1.6.1, when configured with auth_user, allows remote attackers to gain login access as auth_user
Password can be used past expiry in PgBouncer due to auth_query not taking into account Postgres its VALID UNTIL value,
Arbitrary SQL execution during authentication affects PgBouncer before 1.25.1 when the non-default auth_query feature is
Unauthenticated remote attackers can render PgBouncer 1.20.0 through 1.26.0 unresponsive by sending a single crafted Sta
A crafted oversized input to the PgBouncer connection pooler (versions through 1.25.2) triggers an integer overflow in p
Unauthenticated remote attackers can crash PgBouncer through 1.25.2 by sending a malformed SCRAM client-final-message th
Remote denial-of-service in PgBouncer versions before 1.25.2 allows unauthenticated attackers to crash the connection po
Denial of service in PgBouncer before 1.25.2 lets a malicious or malfunctioning PostgreSQL backend crash the connection
GitHub PoC
Exploit-DB