CVE-2021-42237

Exp

Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability.

Published: 2021-11-05 Last update: 2025-11-10 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-42237 is rated Critical Active Threat (99.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 94.37%, 100th percentile). CISA KEV confirms active exploitation (added 2022-03-25) affecting Sitecore / XP. a weakness (CWE-502) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

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

CISA KEV Record for CVE-2021-42237

Name: Sitecore XP Remote Command Execution Vulnerability · CISA KEV detail

Exploit added: 2022-03-25

Action due: 2022-04-15

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2021-42237

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-42237

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 2026-01-31 94.31% 94.37% +0.07%
2 2026-01-04 94.21% 94.31% +0.10%
3 2026-01-01 — 94.21% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42237

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C 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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2021-42237

Affected software / configurations for CVE-2021-42237

Vendor Product Version Raw CPE
sitecore experience_platform 7.5 cpe:2.3:a:sitecore:experience_platform:7.5:-:*:*:*:*:*:*
sitecore experience_platform 7.5 cpe:2.3:a:sitecore:experience_platform:7.5:update1:*:*:*:*:*:*
sitecore experience_platform 7.5 cpe:2.3:a:sitecore:experience_platform:7.5:update2:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:-:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:sp1:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update1:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update2:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update3:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update4:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update5:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update6:*:*:*:*:*:*
sitecore experience_platform 8.0 cpe:2.3:a:sitecore:experience_platform:8.0:update7:*:*:*:*:*:*
sitecore experience_platform 8.1 cpe:2.3:a:sitecore:experience_platform:8.1:-:*:*:*:*:*:*
sitecore experience_platform 8.1 cpe:2.3:a:sitecore:experience_platform:8.1:update1:*:*:*:*:*:*
sitecore experience_platform 8.1 cpe:2.3:a:sitecore:experience_platform:8.1:update2:*:*:*:*:*:*
sitecore experience_platform 8.1 cpe:2.3:a:sitecore:experience_platform:8.1:update3:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:-:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update1:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update2:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update3:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update4:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update5:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update6:*:*:*:*:*:*
sitecore experience_platform 8.2 cpe:2.3:a:sitecore:experience_platform:8.2:update7:*:*:*:*:*:*

References for CVE-2021-42237

cvelogic Threat Intelligence