Fedora EPEL 6 update for tor
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 5 |
| CVE-ID | CVE-2017-8819 CVE-2017-8820 CVE-2017-8821 CVE-2017-8822 CVE-2017-8823 |
| CWE-ID | CWE-20 CWE-476 CWE-119 CWE-416 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software |
Fedora Operating systems & Components / Operating system tor Operating systems & Components / Operating system package or component |
| Vendor | Fedoraproject |
Security Bulletin
This security bulletin contains information about 5 vulnerabilities.
1) Input validation error
EUVDB-ID: #VU37868
Risk: Medium
CVSSv4.0: 6.6 [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 - 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 updates from vendor's repository.
Vulnerable software versionsFedora: 6.0
tor: before 0.2.9.14-1.el6
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2017-8d7c162c64
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) NULL pointer dereference
EUVDB-ID: #VU31386
Risk: Medium
CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2017-8820
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error. A remote attacker can trigger denial of service conditions via a malformed descriptor, aka TROVE-2017-010.
MitigationInstall updates from vendor's repository.
Vulnerable software versionsFedora: 6.0
tor: before 0.2.9.14-1.el6
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2017-8d7c162c64
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Buffer overflow
EUVDB-ID: #VU31387
Risk: Medium
CVSSv4.0: 6.6 [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-2017-8821
CWE-ID:
CWE-119 - Memory corruption
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, an attacker can cause a denial of service (application hang) via crafted PEM input that signifies a public key requiring a password, which triggers an attempt by the OpenSSL library to ask the user for the password, aka TROVE-2017-011.
MitigationInstall updates from vendor's repository.
Vulnerable software versionsFedora: 6.0
tor: before 0.2.9.14-1.el6
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2017-8d7c162c64
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Input validation error
EUVDB-ID: #VU37869
Risk: Low
CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]
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 updates from vendor's repository.
Vulnerable software versionsFedora: 6.0
tor: before 0.2.9.14-1.el6
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2017-8d7c162c64
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
5) Use-after-free
EUVDB-ID: #VU31388
Risk: High
CVSSv4.0: 7.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2017-8823
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to execute arbitrary code.
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, there is a use-after-free in onion service v2 during intro-point expiration because the expiring list is mismanaged in certain error cases, aka TROVE-2017-013.
MitigationInstall updates from vendor's repository.
Vulnerable software versionsFedora: 6.0
tor: before 0.2.9.14-1.el6
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2017-8d7c162c64
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
