Effective 2019 Sep 15, Cisco will no longer publish non-Cisco product alerts. Cisco will continue to publish Security Advisories to address third-party software vulnerabilities per the Cisco Security Vulnerability Policy.
Multivendor Vulnerability Alert
GNOME libxml2 xz_head() Function Denial of Service Vulnerability
A vulnerability in the xz_head() function of the GNOME libxml2 library could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability exists in the xz_head() function, as defined in the xzlib.c source code of the affected software, and is due to a memory consumption condition that could occur in the Lempel-Ziv-Markov (LZMA) decompression feature. An attacker could exploit this vulnerability by persuading a user to open a crafted LZMA file that submits malicious input to the targeted system. A successful exploit could trigger a memory consumption condition, resulting in a DoS condition.
The GNOME Project has confirmed the vulnerability and released a patch.
To exploit this vulnerability, the attacker must use misleading language or instructions to persuade a user on the system to open a LZMA file that submits malicious input.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
Administrators are advised to use an unprivileged account when browsing the Internet.
Administrators are advised to monitor critical systems.
The GNOME Project has released a git commit at the following link: commit e2a9122b
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.