{"id":"CVE-2023-2868","published":"2023-05-24T19:15:09Z","modified":"2026-06-17T05:53:39Z","title":"Barracuda Networks ESG Appliance Improper Input Validation Vulnerability","vendor":"Barracuda Networks","product":"Email Security Gateway (ESG) Appliance","tier":"core","eol":null,"description":{"text":"A remote command injection vulnerability exists in the Barracuda Email Security Gateway (appliance form factor only) product effecting versions 5.1.3.001-9.2.0.006. The vulnerability arises out of a failure to comprehensively sanitize the processing of .tar file (tape archives). The vulnerability stems from incomplete input validation of a user-supplied .tar file as it pertains to the names of the files contained within the archive. As a consequence, a remote attacker can specifically format these file names in a particular manner that will result in remotely executing a system command through Perl's qx operator with the privileges of the Email Security Gateway product. This issue was fixed as part of BNSF-36456 patch. This patch was automatically applied to all customer appliances.","provenance":"source","from":"NVD"},"summary":{"text":"The Barracuda Email Security Gateway (ESG) Appliance contains an improper input validation flaw in its handling of .tar archives, where file names inside a supplied archive are not fully sanitized. An unauthenticated remote attacker with network access can craft a .tar file with specially formatted file names that causes a system command to be executed through Perl's qx operator, requiring no user interaction and running with the privileges of the Email Security Gateway product.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T13:44:51Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.86841,"percentile":0.99744,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2023-05-26","dueDate":"2023-06-16","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://status.barracuda.com/incidents/34kx82j5n4q9;  https://nvd.nist.gov/vuln/detail/CVE-2023-2868","provenance":"source"},"vulncheckKev":{"dateAdded":"2023-05-18","exploitedFirstSeen":"2023-05-18","ransomware":false,"evidence":[{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2023-05-18"},{"url":"https://status.barracuda.com/incidents/34kx82j5n4q9","date":"2023-05-19"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2023-05-26"},{"url":"https://cisa.gov/news-events/alerts/2023/06/15/barracuda-networks-releases-update-address-esg-vulnerability","date":"2023-06-15"},{"url":"https://cloud.google.com/blog/topics/threat-intelligence/barracuda-esg-exploited-globally","date":"2023-06-15"},{"url":"https://www.mandiant.com/resources/blog/barracuda-esg-exploited-globally","date":"2023-06-15"},{"url":"https://cybergeeks.tech/a-technical-analysis-of-the-saltwater-backdoor-used-in-barracuda-0-day-vulnerability-cve-2023-2868-exploitation/","date":"2023-06-26"},{"url":"https://www.mandiant.com/resources/blog/chinese-espionage-tactics","date":"2023-07-18"},{"url":"https://cisa.gov/news-events/alerts/2023/07/28/cisa-releases-malware-analysis-reports-barracuda-backdoors","date":"2023-07-28"},{"url":"https://www.cisa.gov/news-events/analysis-reports/ar23-209a","date":"2023-07-28"}],"evidenceTotal":45,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-77","name":"Improper Neutralization of Special Elements used in a Command"},{"id":"CWE-20","name":"Improper Input Validation"}],"references":[{"url":"https://status.barracuda.com/incidents/34kx82j5n4q9","tags":["Vendor Advisory"]},{"url":"https://www.barracuda.com/company/legal/esg-vulnerability","tags":["Mitigation","Vendor Advisory"]},{"url":"https://status.barracuda.com/incidents/34kx82j5n4q9","tags":["Vendor Advisory"]},{"url":"https://www.barracuda.com/company/legal/esg-vulnerability","tags":["Mitigation","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-2868","tags":["US Government Resource"]}],"techniques":[{"id":"T1566.001","name":"Spearphishing Attachment","tactics":["initial-access"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Input Validation","mappingType":"exploitation_technique","evidence":[],"comment":"CVE-2023-2868 in the Barracuda Email Security Gateway (ESG) had been reportedly exploited for espionage and exfiltration efforts by UNC4841 attributed by Mandiant. Following the exploitation of CVE-2023-2868, malware SALTWATER, SEASPY, and SEASIDE were identified to be used in intrusions.","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Input Validation","mappingType":"primary_impact","evidence":[],"comment":"CVE-2023-2868 in the Barracuda Email Security Gateway (ESG) had been reportedly exploited for espionage and exfiltration efforts by UNC4841 attributed by Mandiant. Following the exploitation of CVE-2023-2868, malware SALTWATER, SEASPY, and SEASIDE were identified to be used in intrusions.","confidence":"high"},{"id":"T1041","name":"Exfiltration Over C2 Channel","tactics":["exfiltration"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Input Validation","mappingType":"secondary_impact","evidence":[],"comment":"CVE-2023-2868 in the Barracuda Email Security Gateway (ESG) had been reportedly exploited for espionage and exfiltration efforts by UNC4841 attributed by Mandiant. Following the exploitation of CVE-2023-2868, malware SALTWATER, SEASPY, and SEASIDE were identified to be used in intrusions.","confidence":"high"},{"id":"T1105","name":"Ingress Tool Transfer","tactics":["command-and-control"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Input Validation","mappingType":"secondary_impact","evidence":[],"comment":"CVE-2023-2868 in the Barracuda Email Security Gateway (ESG) had been reportedly exploited for espionage and exfiltration efforts by UNC4841 attributed by Mandiant. Following the exploitation of CVE-2023-2868, malware SALTWATER, SEASPY, and SEASIDE were identified to be used in intrusions.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2023-34316","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-34316","exploited":true,"exploitedSince":"2023-05-26","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":2,"earliest":"2023-06-20","earliestUrl":"https://github.com/cfielding-r7/poc-cve-2023-2868","repos":[{"name":"cfielding-r7/poc-cve-2023-2868","url":"https://github.com/cfielding-r7/poc-cve-2023-2868","stars":11,"created":"2023-06-20"}]},"metasploit":[{"name":"Barracuda ESG TAR Filename Command Injection","module":"exploit/linux/smtp/barracuda_esg_tarfile_rce","type":"exploit","disclosureDate":"2023-05-23","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/smtp/barracuda_esg_tarfile_rce.rb"}],"first":{"date":"2023-05-23","source":"Metasploit","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/smtp/barracuda_esg_tarfile_rce.rb"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1566.001"],"provenance":"source"},{"stage":"primary","techniques":["T1059"],"provenance":"source"},{"stage":"secondary","techniques":["T1105","T1041"],"provenance":"source"}],"timeline":[{"date":"2023-05-18","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","provenance":"source"},{"date":"2023-05-23","kind":"exploit-public","label":"First public exploit: Metasploit; later: PoC-in-GitHub 2023-06-20","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/smtp/barracuda_esg_tarfile_rce.rb","provenance":"source"},{"date":"2023-05-24","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-2868","provenance":"source"},{"date":"2023-05-26","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2023-05-26","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-34316","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":"Metasploit","daysToKev":2},"priority":{"score":69.8,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1260 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.95,"detail":"percentile 0.9974"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 PoC-in-GitHub repo; 1 Metasploit module"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}