CVE-2021-3935

mediumpriority · track · 32EPSS 0.011 · 66 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.12% (66th) EPSS

CVSS 5.1 · medium

Is it mine?

13 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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

Technical severity, 0–10. One row per scoring source.

8.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.1–8.1

v2.05.1mediumAV:N/AC:H/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 4.9 · impact 6.4

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 5.9

v3.18.1highAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-89USCWE-89US

affected products (13)

Products and version ranges known to be affected.

n/a PgBouncer≤ PgBouncer 1.16.1enisa_euvdEU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.7fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 4.7fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.6 «Смоленск»fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition для «Эльбрус»≤ 8.1 «Ленинград»fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 11fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения PgBouncer≤ 1.16.1fstec_bduRU
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
fedoraproject fedora= 35nvdUScpe:2.3:o:fedoraproject:fedora:*:*:*:*:*:*:*:*
pgbouncer pgbouncer< 1.16.1nvdUScpe:2.3:a:pgbouncer:pgbouncer:*:*:*:*:*:*:*:*
redhat enterprise linux= 7.0nvdUScpe:2.3:o:redhat:enterprise_linux:*:*:*:*:*:*:*:*
Bitnami pgbouncer< 1.16.1osvUSpkg:bitnami/pgbouncer

advisories (1)

Vendor and ecosystem advisories describing this.

BIT-pgbouncer-2021-39352024-03-06vendor · osvUS
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.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd osv NVD CVE.org MITRE

published 2021-11-22modified 2026-06-17

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+1889 more

references (17)

External citations — patches, advisories, analysis.

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