Cisco announced on Wednesday that it has released software updates for its Email Security Appliances (ESA) to address a total of nine vulnerabilities, including denial-of-service (DoS) and filter bypass issues.
The most serious, rated “high severity,” are three DoS flaws in the AsyncOS software for Cisco ESA. The security holes, tracked as CVE-2016-6356, CVE-2016-1486 and CVE-2016-1481, allow a remote, unauthenticated attacker to cause a DoS condition on affected devices using specially crafted emails and malicious attachments.
CVE-2016-1481 and CVE-2016-6356 affect AsyncOS versions 8.0 and prior, 8.5, 9.0, 9.1, 9.5, 9.6, 9.7 and 10.0. Users have been advised to update their installations to versions 9.1.2-041, 9.7.2-065 or 10.0.0-203. The issue identified as CVE-2016-1486 only impacts versions 9.7 and 10.0.
The other vulnerabilities patched by Cisco in its ESA product allow unauthenticated attackers to remotely cause a user to click on a malicious link, trigger a DoS condition, and bypass various filters. Some of these security holes also affect the networking giant’s Web Security Appliances.
All these flaws have been found by Cisco during the resolution of support cases and there is no evidence that any of them have been exploited for malicious purposes.
Cisco also informed customers on Wednesday about a critical unauthorized access vulnerability in the interdevice communications interface of the IP Interoperability and Collaboration System (IPICS) Universal Media Services (UMS).
The vulnerability, identified as CVE-2016-6397, allows a remote attacker to modify configuration parameters and cause the system to become unavailable.
Cisco is conducting an investigation to determine if any of its products are affected by the recently disclosed Linux kernel vulnerability dubbed “Dirty COW.” No products have been confirmed to be vulnerable so far, but the company still needs to analyze many applications and devices.
Dirty COW, identified as CVE-2016-5195, is a local privilege escalation vulnerability for which an exploit has been spotted in the wild. The flaw also affects Android and it has already been leveraged for root exploits.