Ubuntu update for libarchive
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2021-23177 CVE-2021-31566 CVE-2021-36976 |
| CWE-ID | CWE-61 CWE-416 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system libarchive13 (Ubuntu package) Operating systems & Components / Operating system package or component |
| Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) UNIX symbolic link following
EUVDB-ID: #VU61393
Risk: Low
CVSSv3.1: 6.4 [CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-23177
CWE-ID:
CWE-61 - UNIX Symbolic Link (Symlink) Following
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue when extracting files from archive, which can lean to changing ACLs of the target of the link. A local user can create a specially crafted archive, trick the victim into extracting files from it and escalate privileges on the system.
Update the affected package libarchive to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 21.10
libarchive13 (Ubuntu package): before 3.4.3-2ubuntu0.1
External linkshttp://ubuntu.com/security/notices/USN-5291-1
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) UNIX symbolic link following
EUVDB-ID: #VU61394
Risk: Low
CVSSv3.1: 6.4 [CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-31566
CWE-ID:
CWE-61 - UNIX Symbolic Link (Symlink) Following
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue when extracting files from the archive. A local user can create a specially crafted symbolic link to a critical file on the system, place it into an archive and modify modes, times, access control lists, and flags of a file outside of the archive.
Update the affected package libarchive to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 21.10
libarchive13 (Ubuntu package): before 3.4.3-2ubuntu0.1
External linkshttp://ubuntu.com/security/notices/USN-5291-1
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: #VU59459
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-36976
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error in copy_string. A remote attacker can cause a denial of service condition on the target system.
MitigationUpdate the affected package libarchive to the latest version.
Vulnerable software versionsUbuntu: 20.04 - 21.10
libarchive13 (Ubuntu package): before 3.4.3-2ubuntu0.1
External linkshttp://ubuntu.com/security/notices/USN-5291-1
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.
