CVE-2021-3634
Libssh Duplicate Buffer Vulnerability
Description
A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating "secret_hash" of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange.
INFO
Published Date :
Aug. 31, 2021, 5:15 p.m.
Last Modified :
Dec. 22, 2023, 10:15 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
2.8
Public PoC/Exploit Available at Github
CVE-2021-3634 has a 1 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
Affected Products
The following products are affected by CVE-2021-3634
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-3634.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Shell Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-3634 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-3634 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Dec. 22, 2023
Action Type Old Value New Value Added Reference Red Hat, Inc. https://security.gentoo.org/glsa/202312-05 [No types assigned] -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Added Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ [No types assigned] Added Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ [No types assigned] Added Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ [No types assigned] Removed Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/[email protected]/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ Removed Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/[email protected]/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ Removed Reference Red Hat, Inc. https://lists.fedoraproject.org/archives/list/[email protected]/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ -
Modified Analysis by [email protected]
Nov. 16, 2022
Action Type Old Value New Value -
CVE Modified by [email protected]
Oct. 07, 2022
Action Type Old Value New Value Removed CWE Red Hat, Inc. CWE-119 Added CWE Red Hat, Inc. CWE-787 Removed CWE Reason CWE-119 / More specific CWE option available -
Reanalysis by [email protected]
May. 26, 2022
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* versions up to (excluding) 0.9.6 OR *cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* versions from (including) 0.9.1 up to (excluding) 0.9.6 Added CPE Configuration OR *cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* -
Reanalysis by [email protected]
Apr. 25, 2022
Action Type Old Value New Value -
Modified Analysis by [email protected]
Mar. 04, 2022
Action Type Old Value New Value Changed Reference Type https://www.oracle.com/security-alerts/cpujan2022.html No Types Assigned https://www.oracle.com/security-alerts/cpujan2022.html Patch, Third Party Advisory Added CPE Configuration OR *cpe:2.3:a:oracle:mysql_workbench:*:*:*:*:*:*:*:* versions up to (including) 8.0.27 -
CVE Modified by [email protected]
Feb. 07, 2022
Action Type Old Value New Value Added Reference https://www.oracle.com/security-alerts/cpujan2022.html [No Types Assigned] -
Modified Analysis by [email protected]
Oct. 18, 2021
Action Type Old Value New Value Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ Mailing List, Third Party Advisory Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ Mailing List, Third Party Advisory Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ Mailing List, Third Party Advisory Changed Reference Type https://security.netapp.com/advisory/ntap-20211004-0003/ No Types Assigned https://security.netapp.com/advisory/ntap-20211004-0003/ Third Party Advisory Changed CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Oct. 07, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ [No Types Assigned] -
CVE Modified by [email protected]
Oct. 04, 2021
Action Type Old Value New Value Added Reference https://security.netapp.com/advisory/ntap-20211004-0003/ [No Types Assigned] -
CVE Modified by [email protected]
Sep. 29, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ [No Types Assigned] -
CVE Modified by [email protected]
Sep. 29, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ [No Types Assigned] -
Initial Analysis by [email protected]
Sep. 09, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:S/C:N/I:N/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://bugzilla.redhat.com/show_bug.cgi?id=1978810 No Types Assigned https://bugzilla.redhat.com/show_bug.cgi?id=1978810 Issue Tracking, Third Party Advisory Changed Reference Type https://www.debian.org/security/2021/dsa-4965 No Types Assigned https://www.debian.org/security/2021/dsa-4965 Third Party Advisory Added CWE NIST CWE-787 Added CPE Configuration OR *cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* versions up to (excluding) 0.9.6 Added CPE Configuration OR *cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Aug. 31, 2021
Action Type Old Value New Value Added Reference https://www.debian.org/security/2021/dsa-4965 [No Types Assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-3634 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-3634
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.86 }} 0.25%
score
0.82543
percentile