SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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…

HIGH 8.6EPSS 2.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
2.29% probability · 82th percentile
CISA KEV
Not listed
Weakness
CWE-20, CWE-787
Affected
cisco/email security appliance firmware
Source
psirt@cisco.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.