CVE-2019-18849 : Exploit Details and Defense Strategies

An adversary could potentially manipulate a winmail.dat application/ms-tnef attachment in an email message to exploit a heap-based buffer over-read vulnerability in versions before 1.4.18 of tnef. This could allow unauthorized access to the victim's .ssh/authorized_keys file and enable writing to it.

Understanding CVE-2019-18849

In tnef before 1.4.18, an attacker may be able to write to the victim's .ssh/authorized_keys file via an e-mail message with a crafted winmail.dat application/ms-tnef attachment, because of a heap-based buffer over-read involving strdup.

What is CVE-2019-18849?

CVE-2019-18849 is a vulnerability in tnef versions before 1.4.18 that allows an attacker to exploit a heap-based buffer over-read by manipulating a winmail.dat application/ms-tnef attachment in an email message.

The Impact of CVE-2019-18849

This vulnerability could lead to unauthorized access to the victim's .ssh/authorized_keys file and enable writing to it, potentially compromising the victim's system security.

Technical Details of CVE-2019-18849

In-depth technical information about the vulnerability.

Vulnerability Description

The vulnerability in tnef versions before 1.4.18 allows an attacker to perform a heap-based buffer over-read by manipulating a winmail.dat application/ms-tnef attachment.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: Versions before 1.4.18 of tnef

Exploitation Mechanism

The vulnerability can be exploited by an adversary manipulating a winmail.dat application/ms-tnef attachment in an email message.

Mitigation and Prevention

Measures to address and prevent the vulnerability.

Immediate Steps to Take

Update tnef to version 1.4.18 or later to mitigate the vulnerability.
Be cautious when opening email attachments, especially those in the winmail.dat format.

Long-Term Security Practices

Regularly update software and systems to the latest versions.
Implement email security measures to detect and prevent malicious attachments.

Patching and Updates

Ensure timely patching of software and systems to address known vulnerabilities.