The NSS code used for checking PKCS#1 v1.5 was leaking information useful in mounting Bleichenbacher-like attacks. Both the overall correctness of the padding as well as the length of the encrypted message was leaking through timing side-channel. By sending large number of attacker-selected ciphertexts, the attacker would be able to decrypt a previously intercepted PKCS#1 v1.5 ciphertext (for example, to decrypt a TLS session that used RSA key exchange), or forge a signature using the victim's key. The issue was fixed by implementing the implicit rejection algorithm, in which the NSS returns a deterministic random message in case invalid padding is detected, as proposed in the Marvin Attack paper. This vulnerability affects NSS < 3.61.
CVSS Details
- CVSS 3.1 Base Score: 6.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade nss-softokn-freebl-develUpgrade nss-softokn-debuginfoUpgrade nss-softokn-freeblUpgrade nss-softokn-develUpgrade nss-softokn | May 1, 2025 | Dec 12, 2023 |
| Amazon_linux | — | Upgrade nss-softokn | May 13, 2025 | Oct 24, 2023 |
| Debian | — | Upgrade nss | Oct 30, 2023 | Oct 30, 2023 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Dec 12, 2023 |
| Ubuntu | — | Upgrade libnss3 | Apr 11, 2024 | Dec 12, 2023 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jan 20, 2025 | Dec 12, 2023 |
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