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CVE-2020-35730

Roundcube Webmail Cross-Site Scripting (XSS)

6.1 MEDIUMActively exploited (CISA KEV)EPSS 32.9%
  1. Published28 Dec 2020
  2. Added to CISA KEV22 Jun 2023
  3. Remediation due13 Jul 2023
Actively exploited (CISA KEV)

Roundcube Webmail contains a cross-site scripting (XSS) vulnerability that allows an attacker to send a plain text e-mail message with Javascript in a link reference element that is mishandled by linkref_addinindex in rcube_string_replacer.php.

Added to KEV: 22 Jun 2023Federal remediation due: 13 Jul 2023

Description

An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkref_addindex in rcube_string_replacer.php.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

Roundcube Webmail≥ 1.3.0 < 1.3.16 · ≥ 1.4 < 1.4.10 · < 1.2.13
Debian Linux9.0
Fedoraproject Fedora32 · 33

Remediation

Fixed in
Roundcube Webmail≥ 1.3.16

References

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Frequently asked

Is CVE-2020-35730 being actively exploited?

Yes. CVE-2020-35730 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 22 Jun 2023.

How severe is CVE-2020-35730?

CVE-2020-35730 has a CVSS 3.1 base score of 6.1, rated medium. EPSS estimates a 32.9% probability of exploitation.

Which products are affected by CVE-2020-35730?

Affected products include Roundcube Webmail, Debian Linux, Fedoraproject Fedora.

How do I fix CVE-2020-35730?

Upgrade affected software to a fixed version, for example Roundcube Webmail 1.3.16 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2020-35730 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.