CVE-2017-7778 in Firefox
Summary
by MITRE
A number of security vulnerabilities in the Graphite 2 library including out-of-bounds reads, buffer overflow reads and writes, and the use of uninitialized memory. These issues were addressed in Graphite 2 version 1.3.10. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 11/26/2025
The Graphite 2 library vulnerability CVE-2017-7778 represents a critical security flaw in text rendering systems that affects major web browsers and email clients. This vulnerability stems from multiple memory corruption issues within the Graphite 2 library, which is a font rendering system designed to handle complex text layouts and international character sets. The library's implementation contains several dangerous memory access patterns that can be exploited by malicious actors to execute arbitrary code or cause application crashes. The affected software includes Firefox versions prior to 54, Firefox ESR versions prior to 52.2, and Thunderbird versions prior to 52.2, indicating the widespread impact across Mozilla's ecosystem.
The technical implementation of this vulnerability encompasses several distinct memory corruption flaws that fall under the common weakness enumeration CWE-125 for out-of-bounds reads, CWE-787 for out-of-bounds writes, and CWE-457 for use of uninitialized memory. These issues arise when the Graphite 2 library processes font data that contains malformed or maliciously crafted text sequences. The out-of-bounds reads occur when the library attempts to access memory locations beyond the allocated buffer boundaries while parsing font tables, while the buffer overflow conditions happen during memory allocation and data copying operations. The uninitialized memory usage creates exploitable conditions where the library reads memory locations that have not been properly initialized, potentially exposing sensitive data or creating predictable memory states for exploitation.
The operational impact of CVE-2017-7778 extends beyond simple application instability to encompass full system compromise potential through various attack vectors. When exploited, these vulnerabilities can enable attackers to execute arbitrary code within the context of the affected browser or email client, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it affects widely used applications that process untrusted text content from web pages, emails, and other sources. Attackers could craft malicious web pages or email messages containing specially formatted text that triggers the memory corruption when the Graphite 2 library processes the content, making this a prevalent attack surface for remote code execution exploits. The vulnerability affects both desktop and mobile versions of the affected software, amplifying its potential impact across different platforms and user bases.
Mitigation strategies for CVE-2017-7778 focus primarily on immediate software updates and patches to the Graphite 2 library version 1.3.10 or later, which contains the necessary fixes for all identified memory corruption issues. Organizations should prioritize updating Firefox, Firefox ESR, and Thunderbird installations to versions that include the patched Graphite 2 library implementation. System administrators should implement automated patch management processes to ensure all affected applications receive updates promptly. Additional defensive measures include enabling browser security features such as sandboxing and content security policies, which can limit the potential damage from successful exploitation attempts. Network-level protections such as web application firewalls and intrusion detection systems can help detect and block malicious content that attempts to trigger these vulnerabilities. The remediation process should also include monitoring for any signs of exploitation attempts and conducting regular security assessments to verify that all affected systems have been properly updated and patched.