How severe is CVE-2021-33853?

CVE-2021-33853 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-33853 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33853?

CVE-2021-33853 affects X2engine X2crm. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33853?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-33853 published?

CVE-2021-33853 was published on 2022-03-16 and last updated on 2026-06-17.

CVE-2021-33853

CVE-2021-33853 is a medium-severity vulnerability in X2engine X2crm with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: X2engine X2crm
Published: 2022-03-16
Last modified: 2026-06-17

Description

A Cross-Site Scripting (XSS) attack can cause arbitrary code (javascript) to run in a user’s browser while the browser is connected to a trusted website. As the vehicle for the attack, the application targets the users and not the application itself. Additionally, the XSS payload is executed when the user attempts to access any page of the CRM.

Frequently asked questions

What is CVE-2021-33853?: A Cross-Site Scripting (XSS) attack can cause arbitrary code (javascript) to run in a user’s browser while the browser is connected to a trusted website. As the vehicle for the attack, the application targets the users and not the application itself. Additionally, the XSS payload is executed when the user attempts to access any page of the CRM.
How severe is CVE-2021-33853?: CVE-2021-33853 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-33853 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33853?: CVE-2021-33853 affects X2engine X2crm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33853?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33853 published?: CVE-2021-33853 was published on 2022-03-16 and last updated on 2026-06-17.

References

https://cybersecurityworks.com/zerodays/cve-2021-33853-stored-cross-site-scripting-in-x2crm.html

Affected products (1)

cpe:2.3:a:x2engine:x2crm:8.0:*:*:*:*:*:*:*

More vulnerabilities in X2engine X2crm

CVE-2014-2664 — High (CVSS 8.8): Unrestricted file upload vulnerability in the ProfileController::actionUploadPhoto method in…
CVE-2013-5692 — High (CVSS 8.5): Directory traversal vulnerability in X2Engine X2CRM before 3.5 allows remote authenticated administrators to include…
CVE-2015-5074 — High (CVSS 7.5): Incomplete blacklist vulnerability in the FileUploadsFilter class in protected/components/filters/FileUploadsFilter.php…
CVE-2015-5075 — Medium (CVSS 6.8): Cross-site request forgery (CSRF) vulnerability in X2Engine X2CRM before 5.2 allows remote attackers to hijack the…
CVE-2021-27288 — Medium (CVSS 6.1): Cross Site Scripting (XSS) in X2Engine X2CRM v7.1 allows remote attackers to obtain sensitive information by injecting…
CVE-2020-21087 — Medium (CVSS 6.1): Cross Site Scripting (XSS) in X2Engine X2CRM v6.9 and older allows remote attackers to execute arbitrary code by…

All CVEs affecting X2engine X2crm →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →