CVE-2021-31818

Affected versions of Octopus Server are prone to an authenticated SQL injection vulnerability in the Events REST API because user supplied data in the API request isn’t parameterised correctly. Exploiting this vulnerability could allow unauthorised access to database tables.

Published: 2021-06-17 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-31818 is rated Low Risk (33.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.62%). 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-2021-31818

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 0.18% 0.62% +0.44%
2 2025-04-28 0.14% 0.18% +0.04%
3 2025-03-30 — 0.14% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-31818

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]
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-2021-31818

Affected software / configurations for CVE-2021-31818

Vendor Product Version Raw CPE
octopus server >= 2018.9.17, < 2018.13.0 cpe:2.3:a:octopus:server:*:*:*:*:*:*:*:*
octopus server >= 2020.0.0, < 2020.6.0 cpe:2.3:a:octopus:server:*:*:*:*:*:*:*:*
octopus server >= 2020.6.0, < 2020.6.5146 cpe:2.3:a:octopus:server:*:*:*:*:*:*:*:*
octopus server >= 2021.1.0, < 2021.1.7316 cpe:2.3:a:octopus:server:*:*:*:*:*:*:*:*

References for CVE-2021-31818

cvelogic Threat Intelligence