CVE-2025-20393
criticalpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.324 · 98 %ileexploit · PoCDEEUNLRUUSadded 2025-12-17remediate by 2025-12-24
required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
EPSS · scored 2026-10-26
Cisco Multiple Products Improper Input Validation Vulnerability
A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges. This vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Secure Emailcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Email and Web Managercisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (4)
Public proof-of-concept and weaponised exploit code.
- KingHacker353/CVE-2025-20393KingHacker353/CVE-2025-20393PoC · poc_in_github
- redpack-kr/Blackash-CVE-2025-20393CVE-2025-20393PoC · poc_in_github
affected products (67)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- NCSC-2025-0398Kwetsbaarheid in Cisco AsyncOSNL2025-12-17csaf · ncsc_nlNL
Cisco heeft een kwetsbaarheid in Cisco AsyncOS.
- WID-SEC-W-2025-2870Cisco AsyncOS für Secure Email Gateway: Schwachstelle ermöglicht Ausführen von beliebigem Programmcode mit AdministratorrechtenDeutsch2025-12-17csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Cisco AsyncOS und Cisco Secure Email Gateway ausnutzen, um beliebigen Programmcode mit Administratorrechten auszuführen.
- cisco-sa-sma-attack-N9bf4Reports About Cyberattacks Against Cisco Secure Email Gateway And Cisco Secure Email and Web Manager2025-12-17csaf · cisco_csafUS
On December 10, Cisco became aware of a new cyberattack campaign targeting a limited subset of appliances with certain ports open to the internet that are running Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager. This attack allows the threat actors to execute arbitrary commands with root privileges on the underlying operating system of an affected appliance. The ongoing investigation has revealed evidence of a persistence mechanism implanted by the threat actors to maintain a degree of control over compromised appliances. Cisco has remediated the vulnerability that was exploited by the threat actors as part of the cyberattack campaign. For more information about this vulnerability, see the Details ["#details"] section of this advisory. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Cisco strongly recommends that customers follow the guidance provided in the Recommendations ["#Recommendations"]section of this advisory to assess exposure and mitigate risks. Cisco Talos wrote about these attacks in the blog post UAT-9686 actively targets Cisco Secure Email Gateway and Secure Email and Web Manager ["https://blog.talosintelligence.com/uat-9686/"].
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2025-20393cnnvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4cnnvd
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393cnnvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4enisa_euvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4Vendor Advisorynvd
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393US Government Resourcenvd
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