CVE-2010-0175 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsTreeSelection implementation in Mozilla Firefox before 3.0.19 and 3.5.x before 3.5.9, Thunderbird before 3.0.4, and SeaMonkey before 2.0.4 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via unspecified vectors that trigger a call to the handler for the select event for XUL tree items.
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Analysis
by VulDB Data Team • 05/05/2026
The CVE-2010-0175 vulnerability represents a critical use-after-free flaw within the nsTreeSelection component of Mozilla's browser engine, affecting multiple products including Firefox, Thunderbird, and SeaMonkey. This vulnerability stems from improper memory management practices where freed memory locations are accessed after being deallocated, creating a potential exploitation vector for remote attackers. The flaw specifically manifests in the handling of XUL tree items and their associated select event handlers, making it particularly dangerous in web browsing environments where users may encounter malicious content.
The technical implementation of this vulnerability involves the nsTreeSelection class which manages the selection state of tree items in XUL (XML User Interface Language) interfaces. When a select event occurs on XUL tree items, the system calls specific handlers that may reference memory locations that have already been freed. This memory corruption occurs due to insufficient validation of object lifecycles and improper reference counting mechanisms within the Gecko rendering engine. The vulnerability's exploitation requires an attacker to craft malicious content that triggers the specific sequence of events leading to the use-after-free condition, typically through manipulated XUL tree structures in web pages or email content.
From an operational perspective, this vulnerability presents significant risks to end users and organizations as it can be exploited remotely through web-based attacks without requiring user interaction beyond visiting a malicious website. The potential impact includes arbitrary code execution on vulnerable systems, allowing attackers to gain full control over affected browsers and potentially the underlying operating system. Additionally, the vulnerability can be leveraged for denial of service attacks, causing application crashes that disrupt normal user operations and potentially leading to system instability. The widespread adoption of affected Mozilla products means that a successful exploitation could affect millions of users across various platforms and operating systems.
The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software implementations, and represents a classic example of memory safety issues in complex browser engines. Attackers leveraging this vulnerability could potentially bypass security restrictions, execute malicious payloads, or establish persistent access to compromised systems. The ATT&CK framework categorizes this as a memory corruption exploit technique, falling under the broader category of code injection methods that can be used to achieve privilege escalation and persistent access. Organizations should prioritize immediate patching of affected versions, as the vulnerability was actively exploited in the wild prior to the release of security patches. The remediation process involves updating to patched versions of Firefox 3.0.19, Firefox 3.5.9, Thunderbird 3.0.4, and SeaMonkey 2.0.4, which include proper memory management fixes and enhanced validation of object lifecycles. Security teams should also implement network-based protections and monitor for exploitation attempts while conducting regular vulnerability assessments to identify and remediate similar issues in other browser components and third-party applications.