⚠ Actively exploited
Added to CISA KEV on 2023-06-22. Federal agencies required to patch by 2023-07-13. Required action: Apply updates per vendor instructions..

CVE-2020-35730 — Cross-site Scripting in Webmail

CWE-79 — Cross-site Scripting18 documents11 sources
Severity
6.1MEDIUMNVD
EPSS
64.8%
top 1.53%
CISA KEV
KEV
Added 2023-06-22
Due 2023-07-13
Exploit
Exploited in wild
Active exploitation observed
Affected products
3
Roundcube WebmailDebian LinuxFedoraproject Fedora
Timeline
PublishedDec 28
KEV addedJun 22
KEV dueJul 13
Latest updateMay 21
CISA Required Action: Apply updates per vendor instructions.

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 vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NExploitability: 2.8 | Impact: 2.7

Affected Packages1 packages

▶NVDroundcube/webmail1.3.0 — 1.3.16+2

Also affects: Debian Linux 9.0, Fedora 32, 33

Patches

Patch: github.com ↗Patch: github.com ↗

🔴Vulnerability Details

5
OSV
roundcube vulnerabilities↗2022-08-08
▶
GHSA
GHSA-mr5j-h8xf-5m2m: linkref_addindex in rcube_string_replacer↗2022-05-24
▶
CVEList
CVE-2020-35730: An XSS issue was discovered in Roundcube Webmail before 1↗2020-12-28
▶
OSV
CVE-2020-35730: An XSS issue was discovered in Roundcube Webmail before 1↗2020-12-28
▶
VulnCheck
Roundcube Webmail Cross-Site Scripting (XSS) Vulnerability↗2020
▶

📋Vendor Advisories

3
CISA
Roundcube Webmail Cross-Site Scripting (XSS) Vulnerability↗2023-06-22
▶
Ubuntu
Roundcube Webmail vulnerabilities↗2022-08-08
▶
Debian
CVE-2020-35730: roundcube - An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3...↗2020
▶

🕵️Threat Intelligence

9
Bleepingcomputer
Russian hackers breach orgs to track aid routes to Ukraine↗2025-05-21
▶
Bleepingcomputer
Government webmail hacked via XSS bugs in global spy campaign↗2025-05-15
▶
Bleepingcomputer
CISA: Roundcube email server bug now exploited in attacks↗2024-02-12
▶
Securelist
Advanced threat predictions for 2024↗2023-11-14
▶
Securelist
Kaspersky Security Bulletin: APT predictions 2024↗2023-11-14
▶
CVE-2020-35730 — Cross-site Scripting in Webmail | cvebase