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TI-2023-04081 Aliases CVE-2023-4421GHSA-3hpv-hgvq-792m

Observable discrepancy in Mozilla NSS

Priority LOW 30CWE-203Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-203.

Summary

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.

Why it matters now

EPSS 0.00762 55th percentileScored 2026-11-07
Fix Partial NSS (Mozilla): 3.61Red Hat: 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaNSSbefore 3.613.61Patch availableCNA
  • NSS VendorMozilla Affected before 3.61 Fixed in 3.61 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:nss:*:*:*:*:*:*:*:*before 3.6.1VulnerableMozilla
  • cpe:2.3:a:mozilla:nss:*:*:*:*:*:*:*:* Versions before 3.6.1 Vulnerable ·Mozilla

Remediation

  • Fix · CNA NSS (Mozilla) Fixed in 3.61

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Not affected: 3 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-4421
  2. 2026-10-03 Alias added: GHSA-3hpv-hgvq-792m

References

Advisory 1

Other 1

  • TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
  • TI-2021-19417 Out-of-bounds write in Mozilla NSS CVSS 3.1CRITICAL 9.8
  • TI-2020-09921 Out-of-bounds read in nss CVSS 3.1CRITICAL 9.1
  • TI-2016-04582 NULL pointer dereference in Mozilla Network Security Services CVSS 3.1HIGH 7.5
  • TI-2016-01772 The s_mp_div function in lib/freebl/mpi/mpi.c in Mozilla Network Security Services (NSS)… CVSS 3.0MEDIUM 6.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences