CVE-2020-25696
Description
A flaw was found in the psql interactive terminal of PostgreSQL. If an interactive psql session uses \gset when querying a compromised server, this flaw allows an attacker to execute arbitrary code as the operating system account running psql. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Statement
In Red Hat Gluster Storage 3, PostgreSQL (embedded in rhevm-dependencies) was shipped as a part of the Red Hat Gluster Storage Console that is no longer supported for use with Red Hat Gluster Storage 3.5. Red Hat Gluster Storage Web Administration is now the recommended monitoring tool for Red Hat Storage Gluster clusters. In Red Hat Virtualization, the manager appliance uses a vulnerable version of postgresql. Once a fix has been shipped for RHEL 8 the appliance can consume the fix via a regular yum update.
Mitigation
Using \gset with a prefix not found among specially treated variables, e.g. any lowercase string, precludes the attack in an unpatched psql.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Injected code can access resources that the attacker is directly prevented from accessing.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. As a result, code injection can often result in the execution of arbitrary code. Code injection attacks can also lead to loss of data integrity in nearly all cases, since the control-plane data injected is always incidental to data recall or writing.
Non-Repudiation
Technical Impact: Hide Activities
Often the actions performed by injected control code are unlogged.
Acknowledgements
Red Hat would like to thank Nick Cleaton for reporting this issue.
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