Ubuntu update for tar
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2018-20482 CVE-2019-9923 |
| CWE-ID | CWE-835 CWE-476 |
| Exploitation vector | Network |
| Public exploit | Public exploit code for vulnerability #1 is available. |
| Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system tar (Ubuntu package) Operating systems & Components / Operating system package or component |
| Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) Infinite loop
EUVDB-ID: #VU16782
Risk: Low
CVSSv3.1: 5 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2018-20482
CWE-ID:
CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
Exploit availability: No
DescriptionThe vulnerability allows a local attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to the application mishandles file shrinkage during read access when --sparse is used. A local attacker can trigger infinite read loop in sparse_dump_region in sparse.c by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root) and cause denial of service conditions.
MitigationUpdate the affected package tar to the latest version.
Vulnerable software versionsUbuntu: 12.04 - 20.10
tar (Ubuntu package): before 1.30+dfsg-7ubuntu0.20.10.1
External linkshttp://ubuntu.com/security/notices/USN-4692-1
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. However, proof of concept for this vulnerability is available.
2) NULL pointer dereference
EUVDB-ID: #VU18058
Risk: Low
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-2019-9923
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dreference error in sparse.c in when parsing certain archives that have malformed extended headers. A remote attacker can perform a denial of service (DoS) attack.
MitigationUpdate the affected package tar to the latest version.
Vulnerable software versionsUbuntu: 12.04 - 20.10
tar (Ubuntu package): before 1.30+dfsg-7ubuntu0.20.10.1
External linkshttp://ubuntu.com/security/notices/USN-4692-1
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.
