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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.04%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.04% probability · 62th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-89, CWE-295
- Affected
- pgbouncer/pgbouncer · redhat/enterprise linux · fedoraproject/fedora · debian/debian linux
- Source
- patrick@puiterwijk.org
References
- http://www.pgbouncer.org/changelog.html#pgbouncer-116xRelease Notes, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2021251Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/02/msg00016.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNPCV3KRDI5PLLLKADFVIOHACQJLZMLI/
- http://www.pgbouncer.org/changelog.html#pgbouncer-116xRelease Notes, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2021251Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/02/msg00016.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/05/msg00032.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNPCV3KRDI5PLLLKADFVIOHACQJLZMLI/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.