CVE-2023-5388: NSS Timing Side-Channel Attack in Firefox and Thunderbird - Unraveling the Risks and Impacts on User Privacy

With data privacy becoming a high priority for both end-users and experts alike, it is essential to identify potential security vulnerabilities that could risk compromising sensitive information. Recently discovered under the identifier CVE-2023-5388, the Network Security Services (NSS) library used in Mozilla Firefox and Thunderbird was found to be susceptible to a timing side-channel attack when performing RSA decryption. In this post, we will discuss the details of this vulnerability, its potential impacts, and the affected versions.

Exploit Details

The vulnerability in question relates to the RSA decryption algorithm employed by Mozilla's NSS library, which was found to be open to timing side-channel attacks. In layman's terms, an attacker could exploit this vulnerability by monitoring the timing differences in power consumption for various cryptographic operations and gather enough information to deduce the private keys used in the RSA cryptography algorithm. This, in turn, could lead to a complete breakdown of secure communication and of the user's data privacy.

The following code snippet demonstrates how the attack could potentially be carried out

#include <nss.h>
#include <pk11pub.h>
#include <keyhi.h>

void recover_private_key(PK11SymKey* sym_key) {
    // Code to execute the timing side-channel attack.
}

int main() {
    // Initialize NSS library.
    NSS_NoDB_Init(".");
    
    // Load the public key of the target.
    SECKEYPublicKey* public_key = SECKEY_ImportDERPublicKey(...);

    // Generate a random symmetric key.
    PK11SymKey* sym_key = PK11_GenerateRandomKey(...);

    // Wrap the symmetric key with the public key.
    SECItem* wrapped_key = PK11_PubWrapSymKey(CKM_RSA_PKCS, public_key, sym_key);

    // Execute the timing side-channel attack.
    recover_private_key(sym_key);
    
    ...
}

Thunderbird versions prior to 115.9

If you have any of these versions installed on your devices, it is strongly advised to update them to their latest releases to mitigate this security vulnerability.

References and Further Reading

For an in-depth understanding of the vulnerability and the affected NSS implementation, please refer to these resources:

1. Official Mozilla Security Advisory: link
2. Firefox Release Notes (v124.): link
3. Firefox ESR Release Notes (v115.9): link
4. Thunderbird Release Notes (v115.9): link
5. NIST National Vulnerability Database (NVD) - CVE-2023-5388: link

Conclusion

The timing side-channel attack vulnerability (CVE-2023-5388) in Mozilla's NSS library is a critical security risk that affects Firefox and Thunderbird users globally. To ensure data privacy and secure communication, it is imperative to update to the latest releases of these products as soon as possible. Moreover, ongoing vigilance and staying informed about such potential security threats is key to maintaining a secure online presence.

Timeline

Published on: 03/19/2024 12:15:07 UTC
Last modified on: 03/25/2024 17:15:51 UTC