CVE-2021-42763

Couchbase Server before 6.6.3 and 7.x before 7.0.2 stores Sensitive Information in Cleartext. The issue occurs when the cluster manager forwards a HTTP request from the pluggable UI (query workbench etc) to the specific service. In the backtrace, the Basic Auth Header included in the HTTP request, has the "@" user credentials of the node processing the UI request.

Published: 2021-11-02 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-42763 is rated Moderate Risk (45.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.59%). Mandatory action: 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-2021-42763

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 0.17% 0.59% +0.41%
2 2025-03-30 0.27% 0.17% -0.09%
3 2025-03-29 0.27%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42763

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/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:N)
No account or special rights needed—anonymous or random user is enough.
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.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/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:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-42763

Affected software / configurations for CVE-2021-42763

Vendor Product Version Raw CPE
couchbase couchbase_server < 4.6.0 cpe:2.3:a:couchbase:couchbase_server:*:*:*:*:*:*:*:*
couchbase couchbase_server >= 5.0.0, < 6.1.0 cpe:2.3:a:couchbase:couchbase_server:*:*:*:*:*:*:*:*
couchbase couchbase_server >= 6.5.0, <= 6.6.2 cpe:2.3:a:couchbase:couchbase_server:*:*:*:*:*:*:*:*
couchbase couchbase_server 7.0.0 cpe:2.3:a:couchbase:couchbase_server:7.0.0:-:*:*:*:*:*:*
couchbase couchbase_server 7.0.1 cpe:2.3:a:couchbase:couchbase_server:7.0.1:*:*:*:*:*:*:*

References for CVE-2021-42763

cvelogic Threat Intelligence