CVE-2016-5101 in Mail
Summary
by MITRE
Unspecified vulnerability in Opera Mail before 2016-02-16 on Windows allows user-assisted remote attackers to execute arbitrary code via a crafted e-mail message.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/12/2019
The vulnerability identified as CVE-2016-5101 represents a critical security flaw in Opera Mail versions prior to the February 16, 2016 release on Windows operating systems. This issue falls under the category of remote code execution vulnerabilities that can be exploited by attackers with minimal user interaction. The vulnerability stems from insufficient input validation and sanitization mechanisms within the email client's handling of maliciously crafted email messages, creating an attack surface that adversaries can leverage to compromise user systems.
The technical nature of this vulnerability involves the improper processing of email content that triggers a code execution path within the Opera Mail application. Attackers can construct specially crafted email messages containing malicious payloads that, when opened by a victim using the vulnerable version of Opera Mail, initiate unauthorized code execution on the target system. This type of vulnerability is particularly dangerous because it requires only user-assisted exploitation, meaning that simply opening the malicious email message is sufficient for the attack to succeed, without requiring additional user interaction or privilege escalation. The flaw likely resides in how the email client parses and renders email attachments or embedded content, potentially involving buffer overflow conditions, memory corruption issues, or improper handling of file types that could be interpreted as executable code.
From an operational impact perspective, this vulnerability presents significant risks to organizations and individual users who rely on Opera Mail for email communication. The user-assisted nature of the attack means that successful exploitation can occur even in environments with strict security policies, as it only requires a single user to open a malicious email message. This creates a potential vector for widespread compromise, particularly in enterprise environments where email is a primary communication channel. The vulnerability could be exploited in targeted attacks against specific users or used in broader phishing campaigns where social engineering techniques are combined with the technical exploit to maximize impact. Organizations may experience data breaches, system compromise, and potential lateral movement within their networks if attackers successfully leverage this vulnerability.
Security mitigations for CVE-2016-5101 primarily involve immediate software updates and patches provided by Opera to address the vulnerability in the affected versions. Users should ensure their Opera Mail installations are updated to version 37.0.2178.54 or later, which contains the necessary fixes to prevent exploitation of this vulnerability. Additionally, organizations should implement email filtering solutions that can detect and quarantine suspicious email content, particularly focusing on email attachments and embedded links that may contain malicious payloads. Network security controls such as email security gateways and endpoint protection solutions can provide additional layers of defense. From a defensive standpoint, user education and awareness programs should emphasize the importance of not opening suspicious emails, particularly those from unknown senders or those containing unexpected attachments. This vulnerability aligns with ATT&CK technique T1204.002 which covers 'User Execution: Malicious File' and CWE-121 which addresses 'Stack-based Buffer Overflow', indicating the attack vector involves user execution of malicious files and the underlying technical flaw involves buffer overflow conditions. Organizations should also consider implementing email sandboxing and content inspection mechanisms to prevent the automatic execution of potentially malicious content within email applications.