CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
18.1%
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.
Author | Note |
---|---|
mdeslaur | The fix for this issue was incomplete, leading to CVE-2023-5388 |
access.redhat.com/security/cve/CVE-2023-4421
launchpad.net/bugs/cve/CVE-2023-4421
nvd.nist.gov/vuln/detail/CVE-2023-4421
people.redhat.com/~hkario/marvin/
security-tracker.debian.org/tracker/CVE-2023-4421
ubuntu.com/security/notices/USN-6727-1
www.cve.org/CVERecord?id=CVE-2023-4421
www.mozilla.org/en-US/security/advisories/mfsa2023-53/
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
18.1%