CVE catalog
CVE-2023-4421
nss: CVE-2023-4421
- Severity
- Medium
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.76% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | nss | sid | 2:3.131.1-1 | fixed |
| Debian | nss | forky | 2:3.131.1-1 | fixed |
| Debian | nss | trixie | 2:3.110-1+deb13u4 | fixed |
| Debian | nss | trixie-security | 2:3.110-1+deb13u4 | fixed |
| Debian | nss | bookworm | 2:3.87.1-1+deb12u2 | fixed |
| Debian | nss | bookworm-security | 2:3.87.1-1+deb12u4 | fixed |
| Ubuntu | nss | 20.04 | 2:3.45-1ubuntu2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.47-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.47-1ubuntu2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.48-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.4 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.5 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.6 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.7 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.8 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.9 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.98-0ubuntu0.20.04.1 | fixed |
| Ubuntu | nss | 22.04 | 2:3.68-1ubuntu1 | vulnerable |
| Ubuntu | nss | 22.04 | 2:3.68-1ubuntu2 | vulnerable |
| Ubuntu | nss | 22.04 | 2:3.68.2-0ubuntu1 | vulnerable |
| Ubuntu | nss | 22.04 | 2:3.68.2-0ubuntu1.1 | vulnerable |
| Ubuntu | nss | 22.04 | 2:3.68.2-0ubuntu1.2 | vulnerable |
| Ubuntu | nss | 22.04 | 2:3.98-0ubuntu0.22.04.1 | fixed |
| Ubuntu | nss | pro | 2:3.32-1ubuntu3 | vulnerable |
| Ubuntu | nss | pro | 2:3.34-1ubuntu1 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.1 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.2 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.3 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.5 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.6 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.7 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.8 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.9 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.11 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.12 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.13 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.14 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.15 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.16 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.16+esm1 | vulnerable |
| Ubuntu | nss | pro | 2:3.35-2ubuntu2.16+esm2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.45-1ubuntu2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.47-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.47-1ubuntu2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.48-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.1 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.2 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.4 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.5 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.6 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.7 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.8 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.49.1-1ubuntu1.9 | vulnerable |
| Ubuntu | nss | 20.04 | 2:3.98-0ubuntu0.20.04.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | nss | source | sid | 2:3.61-1 | not yet assigned | Not reported | Not reported |
| Debian | nss | source | forky | 2:3.61-1 | not yet assigned | Not reported | Not reported |
| Debian | nss | source | trixie | 2:3.61-1 | not yet assigned | Not reported | Not reported |
| Debian | nss | source | bookworm | 2:3.61-1 | not yet assigned | Not reported | Not reported |
| Ubuntu | nss | deb | 20.04 | 2:3.98-0ubuntu0.20.04.1 | Not reported | USN-6727-1 | Not reported |
| Ubuntu | nss | deb | 22.04 | 2:3.98-0ubuntu0.22.04.1 | Not reported | USN-6727-1 | Not reported |
| Ubuntu | nss | deb | 20.04 | 2:3.98-0ubuntu0.20.04.1 | Not reported | UBUNTU-CVE-2023-4421 | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
References
- [https://ftp.suse.com/pub/projects/security/]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2023-4421]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2023-4421]
- [https://osv.dev/vulnerability/USN-6727-1]
- [https://security-tracker.debian.org/tracker/CVE-2023-4421]
- [https://wid.cert-bund.de/.well-known/csaf/white/2023/wid-sec-w-2023-2787.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]