What is CVE-2023-43770?
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.
The record classifies CVE-2023-43770 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 2 affected-product entries are recorded, across 2 vendors, listed below. The identifier was first published 1134 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 6.1 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS (FIRST)
- 63.6% probability of exploitation in the next 30 days, higher than 99.2% of all scored CVEs
- CISA KEV
- Listed since 2024-02-12, federal remediation deadline 2024-03-04
- Threadlinqs priority
- 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- Published
- 2023-09-22, last modified 2025-10-21
Is CVE-2023-43770 being exploited?
CISA added CVE-2023-43770 to the Known Exploited Vulnerabilities catalog on 2024-02-12, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2024-03-04 under BOD 22-01. Weaponised exploit code for CVE-2023-43770 is publicly available. 4 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 48 in the Threadlinqs vulnerability feed.
- s3cb0y/CVE-2023-43770-POC (github)
- knight0x07/CVE-2023-43770-PoC (github)
- skyllpro/CVE-2021-44026-PoC (github)
- trickest/cve (trickest)
Affected products and versions
How to fix CVE-2023-43770
The record marks a vendor fix as available for CVE-2023-43770. Patch reference: https://github.com/roundcube/roundcubemail/releases/tag/1.6.3. Vendor advisory: https://github.com/roundcube/roundcubemail/commit/e92ec206a886461245e1672d8530cc93c618a49b. Because CVE-2023-43770 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2024-03-04. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2023-43770
2 tracked threats in the Threadlinqs corpus reference CVE-2023-43770, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, public proof-of-concept repositories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.