CVE-2021-3393

An information leak was discovered in postgresql in versions before 13.2, before 12.6 and before 11.11. A user having UPDATE permission but not SELECT permission to a particular column could craft queries which, under some circumstances, might disclose values from that column in error messages. An attacker could use this flaw to obtain information stored in a column they are allowed to write but not read.

Published: 2021-04-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3393 is rated Low Risk (29.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.14%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3393

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.23% 0.14% -0.09%
2 2025-11-18 0.15% 0.23% +0.08%
3 2025-03-30 — 0.15% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3393

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
3.5 2.0 LOW
AV:N/AC:M/Au:S/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 2.9 [email protected]

Weakness enumeration for CVE-2021-3393

OS Trackers for CVE-2021-3393

vendor priority summary link
alpine medium CVE-2021-3393: 4 source package rows (postgresql, postgresql13, postgresql14, postgresql15); 35 state rows across 13 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.17-main, 3.18-community, 3.18-main, 3.19-community, 3.19-main, 3.20-community, 3.20-main, edge-community, edge-main); fixed 21, open 14. https://security.alpinelinux.org/vuln/CVE-2021-3393
debian not yet assigned CVE-2021-3393 not yet assigned priority: Debian including 1 source packages (postgresql-13), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2021-3393
gentoo low CVE-2021-3393: 1 GLSA(s) (202105-32), 1 atom(s) (dev-db/postgresql); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3393
redhat low — https://access.redhat.com/security/cve/CVE-2021-3393
suse low CVE-2021-3393 severity low: SUSE including 564 source package names (10.19:libpq5-13.2-5.6.1, 12-5.1:libpq5-13.2-5.6.1, …), 1189 product×package rows across 107 product lines (Container suse/postgres, Container trento/trento-db, … (107 product lines)): Fixed 540, Known Not Affected 418, Known Affected 231. https://www.suse.com/security/cve/CVE-2021-3393/
ubuntu medium CVE-2021-3393 medium priority: Ubuntu including 6 source packages (postgresql-10, postgresql-12, postgresql-13, postgresql-9.1, postgresql-9.3, postgresql-9.5), 36 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): DNE 25, released 5, needs-triage 3, not-affected 3. https://ubuntu.com/security/CVE-2021-3393

Affected software / configurations for CVE-2021-3393

Vendor Product Version Raw CPE
postgresql postgresql < 11.11 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
postgresql postgresql >= 12.0, < 12.6 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
postgresql postgresql >= 13.0, < 13.2 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
redhat software_collections — cpe:2.3:a:redhat:software_collections:-:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*

References for CVE-2021-3393

cvelogic Threat Intelligence