{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-4421 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2023-4421 is a medium-severity vulnerability in Mozilla NSS, published on 12 Dec 2023. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-4421 and fix it if it is affected.\n\nWhat it is: CVE-2023-4421 is a medium-severity vulnerability in Mozilla NSS, published on 12 Dec 2023. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-4421 in the wild and no public exploit code.\n\nAffected product: Mozilla NSS. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2023-4421/ (Markdown: https://insights.sbomify.com/CVE-2023-4421/index.md)","id":"CVE-2023-4421","markdown":"https://insights.sbomify.com/CVE-2023-4421/index.md","name":"CVE-2023-4421","record":{"aliases":["DEBIAN-CVE-2023-4421","GHSA-3hpv-hgvq-792m","OESA-2026-2612","UBUNTU-CVE-2023-4421"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Mozilla NSS library","requires_auth":"low_privilege","summary":"Timing side-channel in NSS PKCS#1 v1.5 padding checks allows attackers to decrypt TLS sessions or forge signatures.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"nss","vendor":"mozilla"}],"cvss":{"score":6.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-203","name":"Observable Discrepancy"}],"description":"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 \u003c 3.61.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Information disclosure in NSS","id":"CVE-2023-4421","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"information_disclosure","year":"2023"},"n_packages":0,"n_references":2,"next":{"headline":"Cross-site Scripting (XSS) - Stored in cockpit-hq/cockpit","id":"CVE-2023-4422"},"packages":[],"prev":{"headline":"Information disclosure in LMS5xx","id":"CVE-2023-4420"},"products":["NSS"],"published":"2023-12-12","related":[{"cvss_score":9.8,"headline":"Memory corruption in NSS","id":"CVE-2021-43527","kev_date_added":null,"published":"2021-12-08"},{"cvss_score":9.1,"headline":"Memory corruption in nss","id":"CVE-2020-12403","kev_date_added":null,"published":"2021-05-27"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2025-11-04","vendors":["Mozilla"]},"summary":"Timing side-channel in NSS PKCS#1 v1.5 padding checks allows attackers to decrypt TLS sessions or forge signatures.","url":"https://insights.sbomify.com/CVE-2023-4421/"}