CVE-2021-3677

A flaw was found in postgresql. A purpose-crafted query can read arbitrary bytes of server memory. In the default configuration, any authenticated database user can complete this attack at will. The attack does not require the ability to create objects. If server settings include max_worker_processes=0, the known versions of this attack are infeasible. However, undiscovered variants of the attack may be independent of that setting.

Published: 2022-03-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3677 is rated Moderate Risk (51.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.43%). EPSS rose +1.17% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

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-2021-3677

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 2026-06-15 0.25% 1.43% +1.17%
2 2026-05-07 0.19% 0.25% +0.06%
3 2025-11-21 — 0.19% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3677

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/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:L)
Exploitation conditions are straightforward and predictable.
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.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-3677

OS Trackers for CVE-2021-3677

vendor priority summary link
alpine medium CVE-2021-3677: 5 source package rows (postgresql, postgresql12, postgresql13, postgresql14, postgresql15); 32 state rows across 12 repos (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 23, open 9. https://security.alpinelinux.org/vuln/CVE-2021-3677
debian not yet assigned CVE-2021-3677 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-2021-3677
gentoo high CVE-2021-3677: 1 GLSA(s) (202211-04), 1 atom(s) (dev-db/postgresql); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3677
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3677
suse medium CVE-2021-3677 severity moderate: SUSE including 405 source package names (10.19:libpq5-13.4-5.16.2, 12-5.1:libpq5-13.4-5.16.2, …), 1190 product×package rows across 91 product lines (Container suse/postgres, Container trento/trento-db, … (91 product lines)): Known Not Affected 544, Fixed 415, Known Affected 231. https://www.suse.com/security/cve/CVE-2021-3677/
ubuntu medium CVE-2021-3677 medium priority: Ubuntu including 6 source packages (postgresql-10, postgresql-12, postgresql-13, postgresql-9.1, postgresql-9.3, postgresql-9.5), 48 status rows across 8 suites (bionic, focal, hirsute, impish, jammy, trusty, upstream, xenial): DNE 36, not-affected 7, released 5. https://ubuntu.com/security/CVE-2021-3677

Affected software / configurations for CVE-2021-3677

Vendor Product Version Raw CPE
postgresql postgresql >= 11.0, < 11.13 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
postgresql postgresql >= 12.0, < 12.8 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
postgresql postgresql >= 13.0, < 13.4 cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
redhat virtualization 4.0 cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems 8.0 cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 8.0 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*
redhat software_collections 1.0 cpe:2.3:a:redhat:software_collections:1.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-3677

cvelogic Threat Intelligence