CVE-2020-28949
PEAR Archive_Tar Deserialization of Untrusted Data Vulnerability
PEAR Archive_Tar
Archive_Tar through 1.4.10 has :// filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as file:// to overwrite files) can still succeed.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 25 August 2022. US federal agencies were required to remediate it by 15 September 2022.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 84.6%, which is higher than 99.7% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2020-28949 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2020-28949.
What does CVE-2020-28949 affect?
CVE-2020-28949 affects PEAR Archive_Tar. Archive_Tar through 1.4.10 has :// filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as file:// to overwrite files) can still succeed.
How severe is CVE-2020-28949?
CVE-2020-28949 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 84.6%, higher than 99.7% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 15 September 2022.
How should organisations respond to CVE-2020-28949?
Apply the vendor patch for PEAR Archive_Tar as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.