CVE-2021-28089: Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001

High severity · published Mar 19, 2021

CVE-2021-28089

Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001

7.5

CVSS

1.7%

EPSS

On KEV

Description

Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

None

Integrity

None

Availability

High

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)1.7% · higher than 77% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

Fedora · Fedoraproject

33 · source: NVD

Tor · Torproject

before 0.3.5.14; 0.4.4.4 before 0.4.4.8; 0.4.5.0 before 0.4.5.7; 0.4.4.0; 0.4.4.1; 0.4.4.2; +1 more · source: NVD

Affected product

Fedora

Fedoraproject

All Fedora CVEs

References

NVD

https://nvd.nist.gov/vuln/detail/CVE-2021-28089

CVE.org

https://www.cve.org/CVERecord?id=CVE-2021-28089

Release Notes

https://blog.torproject.org/node/2009

Vendor Advisory

https://gitlab.torproject.org/tpo/core/tor/-/issues/40304

lists.fedoraproject.org

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HPDXB2GZHG3VNOTWSXQ3QZVHNV76WCU5/

Third Party Advisory

https://security.gentoo.org/glsa/202107-25