Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 2 |
CVE-ID | CVE-2021-28089 CVE-2021-28090 |
CWE-ID | CWE-400 CWE-617 |
Exploitation vector | Network |
Public exploit | N/A |
Vulnerable software Subscribe |
Tor Client/Desktop applications / Web browsers |
Vendor | tor.eff.org |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
EUVDB-ID: #VU51541
Risk: Medium
CVSSv3.1: 6.5 [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]
CVE-ID: CVE-2021-28089
CWE-ID:
CWE-400 - Resource exhaustion
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources when processing directory data. A remote attacker can force the Tor instance do consume huge amounts of CPU resources and perform a denial of service (DoS) attack.
MitigationInstall updates from vendor's website.
Vulnerable software versionsTor: 0.3.5.0 - 0.4.5.6
External linkshttp://blog.torproject.org/node/2009
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to trick the victim to visit a specially crafted website.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
EUVDB-ID: #VU51542
Risk: Medium
CVSSv3.1: 6.5 [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]
CVE-ID: CVE-2021-28090
CWE-ID:
CWE-617 - Reachable Assertion
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a reachable assertion in servers configured as directory authorities. A remote attacker can send specially crafted data to the server, trigger an assertions failure and crash it.
Install updates from vendor's website.
Vulnerable software versionsTor: 0.3.5.0 - 0.4.5.6
External linkshttp://blog.torproject.org/node/2009
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to trick the victim to visit a specially crafted website.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.