Credential theft via recipient-address XSS
Published Nov 30, 2022 · Updated Apr 25, 2025
Cross-site scripting in SEPPMail's web frontend 11.1.10 allows remote attackers to execute JavaScript via a crafted recipient address. The recipient field is inserted into the generated page without correct HTML encoding, allowing an SVG onload payload to run when a victim sends mail through an attacker-crafted URL. Exploitation requires the victim to open that URL and the attacker to possess a valid SEPPMail session token; the script can capture credentials in the SEPPMail domain.
Summary
What happened
Cross-site scripting in SEPPMail's web frontend 11.1.10 allows remote attackers to execute JavaScript via a crafted recipient address. The recipient field is inserted into the generated page without correct HTML encoding, allowing an SVG onload payload to run when a victim sends mail through an attacker-crafted URL. Exploitation requires the victim to open that URL and the attacker to possess a valid SEPPMail session token; the script can capture credentials in the SEPPMail domain.
The record
- CVE
- CVE-2021-31740
- Published
- Nov 30, 2022
- Updated
- Apr 25, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-79, T1189
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 30, 2022CVE publishedPublication date reported by the CVE source.
- Apr 25, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Pentagrid SEPPmail recipient-address XSS proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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