Vulnerability Report

CVE-2021-3935

Title: Pgbouncer Cryptographic Failures

Cryptographic Failures

Proof Of Concept

No public PoC currently indexed for CVE-2021-3935.

CWE Category CWE-295
Published Date Nov 22, 2021
Modified Date Nov 03, 2025
Exploit Status Not Found
Score 8.1 CVSS v3.1
Exploit Probability (EPSS)
0.08%

Vulnerability Summary

CVE-2021-3935: 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.

Impacted Vendors

P
pgbouncer 1
P
pgbouncer_project 1

Reference Links

http://www.pgbouncer.org/changelog.html#pgbouncer-116x https://bugzilla.redhat.com/show_bug.cgi?id=2021251 https://lists.debian.org/debian-lts-announce/2022/02/msg00016.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNPCV3KRDI5PLLLKADFVIOHACQJLZMLI/ http://www.pgbouncer.org/changelog.html#pgbouncer-116x https://bugzilla.redhat.com/show_bug.cgi?id=2021251 https://lists.debian.org/debian-lts-announce/2022/02/msg00016.html https://lists.debian.org/debian-lts-announce/2025/05/msg00032.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNPCV3KRDI5PLLLKADFVIOHACQJLZMLI/
CVSS v3.1
Source Entity [email protected]
Severity HIGH
8.1
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
5.1
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:H/Au:N/C:P/I:P/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-3935 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.