Ubuntu update for nss
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2023-4421 CVE-2023-5388 CVE-2023-6135 |
| CWE-ID | CWE-385 CWE-203 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system libnss3 (Ubuntu package) Operating systems & Components / Operating system package or component |
| Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Covert Timing Channel
EUVDB-ID: #VU84108
Risk: Medium
CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-4421
CWE-ID:
CWE-385 - Covert Timing Channel
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to 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.
MitigationUpdate the affected package nss to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 23.10
libnss3 (Ubuntu package): before 2:3.98-0ubuntu0.23.10.1
External linkshttp://ubuntu.com/security/notices/USN-6727-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Covert timing channel
EUVDB-ID: #VU85267
Risk: Medium
CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-5388
CWE-ID:
CWE-385 - Covert Timing Channel
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to insufficient fix for #VU84108 (CVE-2023-4421). A remote attacker can perform Marvin attack and gain access to sensitive information.
Update the affected package nss to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 23.10
libnss3 (Ubuntu package): before 2:3.98-0ubuntu0.23.10.1
External linkshttp://ubuntu.com/security/notices/USN-6727-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Observable discrepancy
EUVDB-ID: #VU84568
Risk: Medium
CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-6135
CWE-ID:
CWE-203 - Observable discrepancy
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to a side-channel attack in multiple NSS NIST curves, known as "Minerva". A remote attacker can recover the private key and decrypt data passed between server and client.
Update the affected package nss to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 23.10
libnss3 (Ubuntu package): before 2:3.98-0ubuntu0.23.10.1
External linkshttp://ubuntu.com/security/notices/USN-6727-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
