CVE-2023-43770

Exp

Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.

Published: 2023-09-22 Last update: 2025-10-31 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-43770 is rated Critical Active Threat (85.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 80.84%, 99th percentile). CISA KEV confirms active exploitation (added 2024-02-12) affecting Roundcube / Webmail. cross-site scripting (CWE-79) Unauthenticated remote administrative access may be possible. EPSS rose +1.37% over the last day, indicating growing attacker interest. 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-2023-43770

Name: Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability · CISA KEV detail

Exploit added: 2024-02-12

Action due: 2024-03-04

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Exploit prediction scoring system (EPSS) score for CVE-2023-43770

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 2026-06-10 79.47% 80.84% +1.37%
2 2026-06-02 81.07% 79.47% -1.60%
3 2026-05-22 — 81.07% —

Full EPSS history (72 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-43770

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-43770

OS Trackers for CVE-2023-43770

vendor priority summary link
debian not yet assigned CVE-2023-43770 not yet assigned priority: Debian including 1 source packages (roundcube), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-43770
ubuntu high CVE-2023-43770 high priority: Ubuntu including 1 source packages (roundcube), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 6, not-affected 4, ignored 2. https://ubuntu.com/security/CVE-2023-43770

Affected software / configurations for CVE-2023-43770

Vendor Product Version Raw CPE
roundcube webmail < 1.4.14 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail >= 1.5.0, < 1.5.4 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail >= 1.6.0, < 1.6.3 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2023-43770

cvelogic Threat Intelligence