Multiple vulnerabilities in tor.eff Tor
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2017-8819 CVE-2017-8822 |
| CWE-ID | CWE-20 |
| 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.
1) Input validation error
EUVDB-ID: #VU37868
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-2017-8819
CWE-ID:
CWE-20 - Improper input validation
Exploit availability: No
DescriptionThe 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.
MitigationInstall update from vendor's website.
Vulnerable software versionsTor: 0.3.1 - 0.3.1.8
External linkshttp://blog.torproject.org/new-stable-tor-releases-security-fixes-0319-03013-02914-02817-02516
http://bugs.torproject.org/24244
http://www.debian.org/security/2017/dsa-4054
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.
2) Input validation error
EUVDB-ID: #VU37869
Risk: Low
CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2017-8822
CWE-ID:
CWE-20 - Improper input validation
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
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, relays (that have incompletely downloaded descriptors) can pick themselves in a circuit path, leading to a degradation of anonymity, aka TROVE-2017-012.
MitigationInstall update from vendor's website.
Vulnerable software versionsTor: 0.3.1 - 0.3.1.8
External linkshttp://blog.torproject.org/new-stable-tor-releases-security-fixes-0319-03013-02914-02817-02516
http://bugs.torproject.org/21534
http://bugs.torproject.org/24333
http://www.debian.org/security/2017/dsa-4054
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.
