Debian update for tor



Risk Medium
Patch available YES
Number of vulnerabilities 3
CVE-ID CVE-2021-34548
CVE-2021-34549
CVE-2021-34550
CWE-ID CWE-200
CWE-399
CWE-125
Exploitation vector Network
Public exploit N/A
Vulnerable software
 tor (Debian package)
Operating systems & Components / Operating system package or component

Vendor Debian

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

1) Information disclosure

EUVDB-ID: #VU54229

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-34548

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data. A remote attacker can spoof RELAY_END or RELAY_RESOLVED cell on half-closed streams, which would allow a relay on a circuit to end a stream that wasn't actually built with it.

Mitigation

Update tor package to version 0.3.5.15-1.

Vulnerable software versions

tor (Debian package): 0.3.5.3-alpha-1 - 0.3.5.14-1

CPE2.3 External links

https://www.debian.org/security/2021/dsa-4932


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) Resource management error

EUVDB-ID: #VU54230

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-34549

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the naive unkeyed hash function. A remote attacker can construct circuits with chosen circuit IDs, to create collisions and make the hash table inefficient, resulting in denial of service condition.

Mitigation

Update tor package to version 0.3.5.15-1.

Vulnerable software versions

tor (Debian package): 0.3.5.3-alpha-1 - 0.3.5.14-1

CPE2.3 External links

https://www.debian.org/security/2021/dsa-4932


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) Out-of-bounds read

EUVDB-ID: #VU54231

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-34550

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition during v3 onion service descriptor parsing. A remote attacker can create an onion service descriptor that would crash any client that tried to visit it.

Mitigation

Update tor package to version 0.3.5.15-1.

Vulnerable software versions

tor (Debian package): 0.3.5.3-alpha-1 - 0.3.5.14-1

CPE2.3 External links

https://www.debian.org/security/2021/dsa-4932


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.



###SIDEBAR###