Vulnerability Name:

CVE-2021-3634 (CCN-208281)

Assigned:2021-08-26
Published:2021-08-26
Updated:2022-11-16
Summary: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.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
5.4 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L)
4.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): Low
3.5 Low (REDHAT CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L)
3.1 Low (REDHAT Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Low
CVSS v2 Severity:4.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:S/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
5.5 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:P/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): Partial
Vulnerability Type:CWE-119
CWE-787
Vulnerability Consequences:Gain Access
References:Source: MITRE
Type: CNA
CVE-2021-3634

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1978810

Source: XF
Type: UNKNOWN
libssh-cve20213634-bo(208281)

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2021-f2a020a065

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2021-288925ac19

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2021-ec797b6a96

Source: CCN
Type: oss-sec Mailing List, Thu, 26 Aug 2021 11:58:35 -0300
libssh: Possible heap-buffer overflow when rekeying (CVE-2021-3634)

Source: CONFIRM
Type: Third Party Advisory
https://security.netapp.com/advisory/ntap-20211004-0003/

Source: DEBIAN
Type: Third Party Advisory
DSA-4965

Source: CCN
Type: IBM Security Bulletin 6589939 (MQ Operator)
IBM MQ Operator and Queue manager container images are vulnerable to multiple vulnerabilities from gzip, jackson-databind, libssh, gnutls, nettle and zlib

Source: CCN
Type: IBM Security Bulletin 6597537 (App Connect Enterprise Certified Container)
IBM App Connect Enterprise Certified Container operands may be vulnerable to arbitrary code execution due to CVE-2021-3634

Source: CCN
Type: IBM Security Bulletin 6610303 (Watson Speech Services Cartridge for Cloud Pak for Data)
IBM Watson Speech Services Cartridge for IBM Cloud Pak for Data is vulnerable to a heap-based buffer overflow in libssh, caused by improper bounds checking.(CVE-2021-3634).

Source: CCN
Type: IBM Security Bulletin 6615217 (Robotic Process Automation for Cloud Pak)
Multiple vulnerabilities may affect IBM Robotic Process Automation for Cloud Pak

Source: CCN
Type: IBM Security Bulletin 6831813 (Netcool Operations Insight)
Netcool Operations Insight v1.6.6 contains fixes for multiple security vulnerabilities.

Source: CCN
Type: IBM Security Bulletin 6831853 (QRadar SIEM)
IBM QRadar SIEM Application Framework Base Image is vulnerable to using components with Known Vulnerabilities

Source: CCN
Type: IBM Security Bulletin 6856409 (Cloud Pak for Security)
IBM Cloud Pak for Security includes components with multiple known vulnerabilities

Source: CCN
Type: libssh Web site
libssh 0.9.6 security release

Source: CCN
Type: Oracle CPUJan2022
Oracle Critical Patch Update Advisory - January 2022

Source: MISC
Type: Patch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.html

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2021-3634

Vulnerable Configuration:Configuration 1:
  • cpe:/a:libssh:libssh:*:*:*:*:*:*:*:* (Version >= 0.9.1 and < 0.9.6)

    • Configuration 2:
  • cpe:/a:redhat:virtualization:4.0:*:*:*:*:*:*:*
  • OR cpe:/o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*

    • Configuration 3:
  • cpe:/o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • OR cpe:/o:debian:debian_linux:11.0:*:*:*:*:*:*:*

    • Configuration 4:
  • cpe:/o:fedoraproject:fedora:33:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:34:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:35:*:*:*:*:*:*:*

    • Configuration 5:
  • cpe:/a:oracle:mysql_workbench:*:*:*:*:*:*:*:* (Version <= 8.0.27)

    • Configuration 6:
  • cpe:/a:netapp:cloud_backup:-:*:*:*:*:*:*:*

    • Configuration RedHat 1:
  • cpe:/a:redhat:enterprise_linux:8:*:*:*:*:*:*:*

    • Configuration RedHat 2:
  • cpe:/a:redhat:enterprise_linux:8::appstream:*:*:*:*:*

    • Configuration RedHat 3:
  • cpe:/o:redhat:enterprise_linux:8:*:*:*:*:*:*:*

    • Configuration RedHat 4:
  • cpe:/o:redhat:enterprise_linux:8::baseos:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:libssh:libssh:0.9.4:*:*:*:*:*:*:*
  • AND
  • cpe:/a:ibm:qradar_security_information_and_event_manager:7.4:-:*:*:*:*:*:*
  • OR cpe:/a:ibm:app_connect_enterprise_certified_container:4.1:*:*:*:*:*:*:*
  • OR cpe:/a:ibm:robotic_process_automation_for_cloud_pak:21.0.1:*:*:*:*:*:*:*
  • OR cpe:/a:ibm:robotic_process_automation_for_cloud_pak:21.0.2:*:*:*:*:*:*:*
  • OR cpe:/a:ibm:cloud_pak_for_security:1.10.0.0:*:*:*:*:*:*:*
  • OR cpe:/a:ibm:cloud_pak_for_security:1.10.6.0:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:7676
    P
    		libssh-config-0.9.6-150400.1.5 on GA media (Moderate)
    2023-06-12
    oval:org.opensuse.security:def:3084
    P
    		gnome-settings-daemon-3.20.1-50.16.1 on GA media (Moderate)
    2022-06-28
    oval:org.opensuse.security:def:94714
    P
    		libssh-config-0.9.6-150400.1.5 on GA media (Moderate)
    2022-06-22
    oval:com.redhat.rhsa:def:20222031
    P
    		RHSA-2022:2031: libssh security, bug fix, and enhancement update (Low)
    2022-05-10
    oval:org.opensuse.security:def:112853
    P
    		libssh-config-0.9.6-1.2 on GA media (Moderate)
    2022-01-17
    oval:org.opensuse.security:def:106316
    P
    		Security update for busybox (Important) (in QA)
    2022-01-14
    BACK
    libssh libssh *
    redhat virtualization 4.0
    redhat enterprise linux 8.0
    debian debian linux 10.0
    debian debian linux 11.0
    fedoraproject fedora 33
    fedoraproject fedora 34
    fedoraproject fedora 35
    oracle mysql workbench *
    netapp cloud backup -
    libssh libssh 0.9.4
    ibm qradar security information and event manager 7.4 -
    ibm app connect enterprise certified container 4.1
    ibm robotic process automation for cloud pak 21.0.1
    ibm robotic process automation for cloud pak 21.0.2
    ibm cloud pak for security 1.10.0.0
    ibm cloud pak for security 1.10.6.0