#VU80523 Out-of-bounds write in libssh2 - CVE-2020-22218

Vulnerability identifier: #VU80523

Vulnerability 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-2020-22218

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libssh2
Client/Desktop applications / Software for system administration

Vendor: libssh2.org

Description

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

The vulnerability exists due to usage of an uninitialized value within the _libssh2_transport_read() function in transport.c. A remote attacker can pass specially crafted input to the application, trigger memory corruption and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libssh2: 1.9.0

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External links
https://github.com/libssh2/libssh2/pull/476
https://github.com/libssh2/libssh2/commit/0b44e558f311671f6e6d14c559bc1c9bda59b8df

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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.