Vulnerability Name:

CVE-2021-28089 (CCN-198458)

Assigned:2021-03-18
Published:2021-03-18
Updated:2022-05-16
Summary: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 v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-400
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-28089

Source: CCN
Type: Tor Blog, March 16, 2021
New releases (with security fixes): Tor 0.3.5.14, 0.4.4.8, and 0.4.5.7

Source: CONFIRM
Type: Release Notes, Vendor Advisory
https://blog.torproject.org/node/2009

Source: XF
Type: UNKNOWN
tor-cve202128089-dos(198458)

Source: MISC
Type: Vendor Advisory
https://gitlab.torproject.org/tpo/core/tor/-/issues/40304

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2021-e68317166d

Source: GENTOO
Type: Third Party Advisory
GLSA-202107-25

Vulnerable Configuration:Configuration 1:
  • cpe:/a:torproject:tor:0.4.4.1:alpha:*:*:*:*:*:*
  • OR cpe:/a:torproject:tor:0.4.4.0:alpha:*:*:*:*:*:*
  • OR cpe:/a:torproject:tor:*:*:*:*:*:*:*:* (Version >= 0.4.5.0 and < 0.4.5.7)
  • OR cpe:/a:torproject:tor:*:*:*:*:*:*:*:* (Version < 0.3.5.14)
  • OR cpe:/a:torproject:tor:0.4.4.2:alpha:*:*:*:*:*:*
  • OR cpe:/a:torproject:tor:0.4.4.3:alpha:*:*:*:*:*:*
  • OR cpe:/a:torproject:tor:*:*:*:*:*:*:*:* (Version >= 0.4.4.4 and < 0.4.4.8)

    • Configuration 2:
  • cpe:/o:fedoraproject:fedora:33:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:113539
    P
    		tor-0.4.6.7-2.2 on GA media (Moderate)
    2022-01-17
    oval:org.opensuse.security:def:106934
    P
    		tor-0.4.6.7-2.2 on GA media (Moderate)
    2021-10-01
    oval:org.opensuse.security:def:11192
    P
    		Security update for tor (Moderate)
    2021-03-25
    oval:org.opensuse.security:def:96460
    P
    		Security update for tor (Moderate)
    2021-03-25
    oval:org.opensuse.security:def:103150
    P
    		Security update for tor (Moderate)
    2021-03-25
    oval:org.opensuse.security:def:109807
    P
    		Security update for tor (Moderate)
    2021-03-25
    oval:org.opensuse.security:def:111283
    P
    		Security update for tor (Moderate)
    2021-03-22
    BACK
    torproject tor 0.4.4.1 alpha
    torproject tor 0.4.4.0 alpha
    torproject tor *
    torproject tor *
    torproject tor 0.4.4.2 alpha
    torproject tor 0.4.4.3 alpha
    torproject tor *
    fedoraproject fedora 33