CVE-2021-3634
CVSS V2 Medium 4
CVSS V3 Medium 6.5
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.
Overview
- CVE ID
- CVE-2021-3634
- Assigner
- secalert@redhat.com
- Vulnerability Status
- Analyzed
- Published Version
- 2021-08-31T17:15:08
- Last Modified Date
- 2022-11-16T03:31:13
Weakness Enumerations
CPE Configuration (Product)
| CPE | Vulnerable | Operator | Version Start | Version End |
|---|---|---|---|---|
| cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* | 1 | OR | 0.9.1 | 0.9.6 |
| cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* | 1 | OR | ||
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:a:oracle:mysql_workbench:*:*:*:*:*:*:*:* | 1 | OR | 8.0.27 | |
| cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* | 1 | OR |
CVSS Version 2
- Version
- 2.0
- Vector String
- AV:N/AC:L/Au:S/C:N/I:N/A:P
- Access Vector
- NETWORK
- Access Compatibility
- LOW
- Authentication
- SINGLE
- Confidentiality Impact
- NONE
- Integrity Impact
- NONE
- Availability Impact
- PARTIAL
- Base Score
- 4
- Severity
- MEDIUM
- Exploitability Score
- 8
- Impact Score
- 2.9
CVSS Version 3
- Version
- 3.1
- Vector String
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Attack Vector
- NETWORK
- Attack Compatibility
- LOW
- Privileges Required
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality Impact
- NONE
- Availability Impact
- HIGH
- Base Score
- 6.5
- Base Severity
- MEDIUM
- Exploitability Score
- 2.8
- Impact Score
- 3.6
References
| Reference URL | Reference Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1978810 | Issue Tracking Third Party Advisory |
| https://www.debian.org/security/2021/dsa-4965 | Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SVWAAB2XMKEUMPMDALINKAA4U2QM4LNG/ | Mailing List Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JKYD3ZRAMDAQX3ZW6THHUF3GXN7FF6B4/ | Mailing List Third Party Advisory |
| https://security.netapp.com/advisory/ntap-20211004-0003/ | Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DRK67AJCWYYVAGF5SGAHNZXCX3PN3ZFP/ | Mailing List Third Party Advisory |
| https://www.oracle.com/security-alerts/cpujan2022.html | Patch Third Party Advisory |
Sources
| Source Name | Source URL |
|---|---|
| NIST | https://nvd.nist.gov/vuln/detail/CVE-2021-3634 |
| MITRE | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3634 |
History
| Created | Old Value | New Value | Data Type | Notes |
|---|---|---|---|---|
| 2022-05-10 06:26:48 | Added to TrackCVE | |||
| 2022-12-05 09:23:31 | 2021-08-31T17:15Z | 2021-08-31T17:15:08 | CVE Published Date | updated |
| 2022-12-05 09:23:31 | 2022-11-16T03:31:13 | CVE Modified Date | updated | |
| 2022-12-05 09:23:31 | Analyzed | Vulnerability Status | updated |