Ubuntu update for libsepol
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2021-36084 CVE-2021-36085 CVE-2021-36086 CVE-2021-36087 |
| CWE-ID | CWE-416 CWE-125 |
| Exploitation vector | Local |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system sepol-utils (Ubuntu package) Operating systems & Components / Operating system package or component libsepol1 (Ubuntu package) Operating systems & Components / Operating system package or component |
| Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Use-after-free
EUVDB-ID: #VU62660
Risk: Low
CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-36084
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the __cil_verify_classperms() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack.
Update the affected package libsepol to the latest version.
Vulnerable software versionsUbuntu: 16.04 - 21.10
sepol-utils (Ubuntu package): before 3.1-1ubuntu2.1
libsepol1 (Ubuntu package): before 3.1-1ubuntu2.1
External linkshttp://ubuntu.com/security/notices/USN-5391-1
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Use-after-free
EUVDB-ID: #VU62661
Risk: Low
CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-36085
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the __cil_verify_classperms() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack. MitigationUpdate the affected package libsepol to the latest version.
Vulnerable software versionsUbuntu: 16.04 - 21.10
sepol-utils (Ubuntu package): before 3.1-1ubuntu2.1
libsepol1 (Ubuntu package): before 3.1-1ubuntu2.1
External linkshttp://ubuntu.com/security/notices/USN-5391-1
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Use-after-free
EUVDB-ID: #VU62662
Risk: Low
CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-36086
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the cil_reset_classpermission() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack. MitigationUpdate the affected package libsepol to the latest version.
Vulnerable software versionsUbuntu: 16.04 - 21.10
sepol-utils (Ubuntu package): before 3.1-1ubuntu2.1
libsepol1 (Ubuntu package): before 3.1-1ubuntu2.1
External linkshttp://ubuntu.com/security/notices/USN-5391-1
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Out-of-bounds read
EUVDB-ID: #VU62663
Risk: Low
CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-36087
CWE-ID:
CWE-125 - Out-of-bounds read
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error in the ebitmap_match_any() function within the CIL compiler in SELinux. A local user can trigger an out-of-bounds read error and perform denial of service attack.
MitigationUpdate the affected package libsepol to the latest version.
Vulnerable software versionsUbuntu: 16.04 - 21.10
sepol-utils (Ubuntu package): before 3.1-1ubuntu2.1
libsepol1 (Ubuntu package): before 3.1-1ubuntu2.1
External linkshttp://ubuntu.com/security/notices/USN-5391-1
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
