Security readout for executives and security teams
Plain-English summary
Some Juniper SRX firewalls used as UAC enforcers may enforce access policy incorrectly, allowing users to reach restricted network resources. This is not a universal SRX issue; it depends on affected Junos OS versions and a specific Infranet Controller range configuration.
Executive priority
Treat as high priority for environments using Juniper SRX as UAC enforcement. It can undermine network segmentation policy, but scope is configuration-dependent and not default for all SRX deployments.
Technical view
CVE-2020-1637 is a CWE-288 authentication bypass in Junos OS on SRX Series configured as a Junos OS Enforcer. The issue can occur when the Infranet Controller uses an IP address range rather than address/netmask, causing UAC policy bypass with low confidentiality and integrity impact.
Likely exposure
Exposure is limited to Juniper SRX Series running affected Junos OS releases and configured as Junos OS Enforcer devices. The source states Enforcer CLI settings are disabled by default, reducing default exposure. Confirm whether UAC and Infranet Controller policy ranges are in use.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not marked KEV. The vulnerability is network-accessible, requires no privileges or user interaction, and has low attack complexity, so exposed eligible configurations deserve prompt review.
Researcher notes
Affected trains include 12.3X48, 15.1X49, 17.3, 17.4, 18.1 through 18.4, and 19.1 through 19.4 before specified fixed releases. Evidence is limited to vendor/CVE data; no public exploit status is provided.
Mitigation direction
- Upgrade Junos OS to the fixed release listed for the deployed train.
- Review Juniper JSA11018 for the exact vendor workaround and upgrade guidance.
- Check Infranet Controller IP range formatting against Juniper guidance.
- Prioritize SRX devices enforcing UAC policy for sensitive network segments.
Validation and detection
- Inventory SRX devices and Junos OS versions across supported trains.
- Confirm whether each SRX is configured as a Junos OS Enforcer.
- Review Infranet Controller ranges for range-versus-netmask configuration.
- Test that UAC policy denies unauthorized resource access after remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-288: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-1637 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N3.92.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.juniper.net/JSA11018CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Authentication Bypass Using an Alternate Path or Channel
Authentication Bypass Using an Alternate Path or Channel represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.