CVE-2014-1491 in Firefox
Summary
by MITRE
Mozilla Network Security Services (NSS) before 3.15.4, as used in Mozilla Firefox before 27.0, Firefox ESR 24.x before 24.3, Thunderbird before 24.3, SeaMonkey before 2.24, and other products, does not properly restrict public values in Diffie-Hellman key exchanges, which makes it easier for remote attackers to bypass cryptographic protection mechanisms in ticket handling by leveraging use of a certain value.
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Analysis
by VulDB Data Team • 11/25/2025
The vulnerability identified as CVE-2014-1491 represents a critical weakness in the Mozilla Network Security Services (NSS) cryptographic library that affected multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey. This flaw specifically impacts the implementation of Diffie-Hellman key exchange mechanisms within the SSL/TLS protocol stack, creating a significant security risk that could be exploited by remote attackers to undermine cryptographic protections. The vulnerability stems from insufficient validation of public values during the key exchange process, allowing malicious actors to manipulate the cryptographic parameters and potentially compromise the security of encrypted communications.
The technical flaw manifests in the improper restriction of public values used in Diffie-Hellman key exchanges, where the NSS library fails to adequately validate the mathematical properties of the public parameters presented during the cryptographic handshake. This weakness is particularly concerning because it directly affects the ticket handling mechanism in SSL/TLS implementations, which are critical for maintaining session continuity and security in web communications. The vulnerability enables attackers to leverage specific mathematical values that should be restricted or validated to prevent exploitation of the cryptographic protocol. This issue is classified under CWE-327, which deals with the use of a broken or risky cryptographic algorithm, and specifically relates to weak key exchange parameters that can be manipulated by adversaries.
The operational impact of this vulnerability extends beyond simple cryptographic weakness to potentially enable man-in-the-middle attacks and session hijacking scenarios where attackers can exploit the flawed Diffie-Hellman implementation to bypass security protections. Remote attackers can manipulate the key exchange process by presenting specially crafted public values that, when accepted by the vulnerable system, allow them to establish connections with compromised cryptographic integrity. This weakness particularly affects the security of web browsing sessions, email communications, and other applications that rely on NSS for secure communications. The vulnerability creates opportunities for attackers to decrypt communications, impersonate services, or otherwise compromise the confidentiality and integrity of data transmitted through affected systems, making it a serious concern for organizations relying on these Mozilla products.
Organizations should prioritize immediate patching of affected systems to address this vulnerability, as the security implications extend to all versions of the affected products that were released prior to the remediation. The recommended mitigation strategy involves updating to the patched versions of Mozilla Firefox, Thunderbird, SeaMonkey, and any other products that utilize NSS version 3.15.4 or earlier. Security teams should also implement monitoring for potential exploitation attempts and consider implementing additional network-level controls to detect and prevent manipulation of cryptographic parameters. The vulnerability demonstrates the critical importance of proper cryptographic parameter validation and highlights the need for continuous security auditing of cryptographic libraries. Organizations should also review their deployment practices to ensure that all systems utilizing these components are promptly updated to versions that contain the necessary cryptographic fixes, as outlined in the MITRE ATT&CK framework's cryptographic operations category where such weaknesses can enable adversary access to sensitive information through protocol manipulation techniques.