Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Cisco IP Phones

1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

EUVDB-ID: #VU64450

Risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-20817

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No

Description

The vulnerability allows a remote attacker to impersonate another user's phone. 

The vulnerability exists due to due to improper key generation during the manufacturing process that could result in duplicated manufactured keys installed on multiple devices. A remote attacker can perform a machine-in-the-middle attack and impersonate another user's phone if the Cisco Unified Communications Manager (CUCM) is in secure mode.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Unified IP Phone 6901: All versions

ATA 187 Analog Telephone Adapter: All versions

Unified IP Phone 6911: All versions

Unified IP Phone 6921: All versions

Unified IP Phone 6941: All versions

Unified IP Phone 6945: All versions

Unified IP Phone 6961: All versions

Unified IP Phone 8941: All versions

Unified IP Phone 8945: All versions

Unified IP Phone 8961: All versions

Unified IP Phone 9951: All versions

Unified IP Phone 9971: All versions

CPE2.3

• cpe:2.3:h:cisco_systems:unified_ip_phone_6901:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:h:cisco_systems:ata_187_analog_telephone_adapter:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_6911:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_6921:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_6941:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_6945:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_6961:*:*:*:*:*:cisco_unified_ip_phone_6900_series:*:*
• cpe:2.3:a:cisco_systems:unified_ip_phone_8941:*:*:*:*:*:unified_ip_phone_8900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_8945:*:*:*:*:*:unified_ip_phone_8900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_8961:*:*:*:*:*:unified_ip_phone_8900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_9951:*:*:*:*:*:cisco_unified_ip_phones_9900_series:*:*
• cpe:2.3:h:cisco_systems:unified_ip_phone_9971:*:*:*:*:*:cisco_unified_ip_phones_9900_series:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cp6901-dup-cert-82jdJGe4

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 send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.