CVE-2023-25136 - Double Free

Severity

98%

Complexity

39%

Confidentiality

98%

OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be triggered by an unauthenticated attacker in the default configuration; however, the vulnerability discoverer reports that "exploiting this vulnerability will not be easy."

OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be triggered by an unauthenticated attacker in the default configuration. One third-party report states "remote code execution is theoretically possible."

OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote attacker in the default configuration, to jump to any location in the sshd address space. One third-party report states "remote code execution is theoretically possible."

CVSS 3.1 Base Score 9.8. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

CVSS 3.1 Base Score 6.5. CVSS Attack Vector: network. CVSS Attack Complexity: high. CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H).

Demo Examples

Double Free

CWE-415

Double Free

CWE-415

While contrived, this code should be exploitable on Linux distributions which do not ship with heap-chunk check summing turned on.


               
}
free(buf1R2);

Overview

First reported 2 years ago

2023-02-03 06:15:00

Last updated 1 year ago

2023-11-07 04:08:00

Affected Software

NetApp ONTAP Select Deploy Administration Utility

References

https://ftp.openbsd.org/pub/OpenBSD/patches/7.2/common/017_sshd.patch.sig

https://bugzilla.mindrot.org/show_bug.cgi?id=3522

https://github.com/openssh/openssh-portable/commit/486c4dc3b83b4b67d663fb0fa62bc24138ec3946

https://www.openwall.com/lists/oss-security/2023/02/02/2

https://jfrog.com/blog/openssh-pre-auth-double-free-cve-2023-25136-writeup-and-proof-of-concept/

https://news.ycombinator.com/item?id=34711565

https://ftp.openbsd.org/pub/OpenBSD/patches/7.2/common/017_sshd.patch.sig

Patch, Vendor Advisory

https://bugzilla.mindrot.org/show_bug.cgi?id=3522

Exploit, Issue Tracking, Third Party Advisory

https://github.com/openssh/openssh-portable/commit/486c4dc3b83b4b67d663fb0fa62bc24138ec3946

Patch, Third Party Advisory

https://www.openwall.com/lists/oss-security/2023/02/02/2

Exploit, Mailing List, Third Party Advisory

https://jfrog.com/blog/openssh-pre-auth-double-free-cve-2023-25136-writeup-and-proof-of-concept/

Exploit, Third Party Advisory

https://news.ycombinator.com/item?id=34711565

Issue Tracking, Third Party Advisory

[oss-security] 20230213 Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

[oss-security] 20230222 Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

[oss-security] 20230222 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

[oss-security] 20230223 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

[oss-security] 20230306 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

[oss-security] 20230213 Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

[oss-security] 20230222 Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

[oss-security] 20230222 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

[oss-security] 20230223 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

[oss-security] 20230306 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

[oss-security] 20230309 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

https://security.netapp.com/advisory/ntap-20230309-0003/

FEDORA-2023-1176c8b10c

FEDORA-2023-123647648e

GLSA-202307-01

[oss-security] 20230309 Re: Re: double-free vulnerability in OpenSSH server 9.1 (CVE-2023-25136)

Mailing List, Third Party Advisory

https://security.netapp.com/advisory/ntap-20230309-0003/

Third Party Advisory

FEDORA-2023-1176c8b10c

Mailing List

FEDORA-2023-123647648e

Mailing List

GLSA-202307-01

Third Party Advisory

FEDORA-2023-1176c8b10c

FEDORA-2023-123647648e

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