#VU37868 Input validation error in Tor - CVE-2017-8819
Published: December 3, 2017 / Updated: August 8, 2020
Vulnerability identifier: #VU37868
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2017-8819
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Tor
Tor
Software vendor:
tor.eff.org
tor.eff.org
Description
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, the replay-cache protection mechanism is ineffective for v2 onion services, aka TROVE-2017-009. An attacker can send many INTRODUCE2 cells to trigger this issue.
Remediation
Install update from vendor's website.