Buffer overflow in Cisco Email Security Appliance (Esa)
CVE-2018-15453
A vulnerability in the Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification or S/MIME Public Key Harvesting features of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause an affected device to corrupt system memory. A successful exploit could cause the filtering process to unexpectedly reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to improper input validation of S/MIME-signed emails. An attacker could exploit this vulnerability by sending a malicious S/MIME-signed email through a targeted device. If Decryption and Verification or Public Key Harvesting is configured, the filtering process could crash due to memory corruption and restart, resulting in a DoS condition. The software could then resume processing the same S/MIME-signed email, causing the filtering process to crash and restart again. A successful exploit could allow the attacker to cause a permanent DoS condition. This vulnerability may require manual intervention to recover the ESA.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.023 (82.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Cisco Email Security Appliance (Esa) — versions n/a
- Cisco Email_security_appliance_firmware — versions 11.0.1-401, 11.1.0-131
Weakness classification (CWE)
References
- psirt@cisco.com (x_refsource_CISCO, vendor-advisory, Vendor Advisory)
- psirt@cisco.com (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_BID)
Frequently asked questions
- What is CVE-2018-15453?
- CVE-2018-15453 is a high-severity vulnerability in Cisco Email Security Appliance (Esa), classified under Improper Input Validation. CVSS score: 8.6/10. Published 2019-01-10.
- How severe is CVE-2018-15453?
- High severity. CVSS v3 base score is 8.6 out of 10.