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CVE Record

CVE-2021-23718: Server-side Request Forgery (SSRF)

The package ssrf-agent before 1.0.5 are vulnerable to Server-side Request Forgery (SSRF) via the defaultIpChecker function. It fails to properly validate if the IP requested is private.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-23718 affects the npm package ssrf-agent before 1.0.5. The library’s IP checking could fail to recognize private IP destinations, allowing a user-influenced request to reach internal resources. Business risk is mainly exposure of sensitive internal data, not direct system takeover.

Executive priority

Prioritize remediation during normal dependency patching, escalating if vulnerable services are internet-facing or can fetch attacker-supplied URLs. The main business concern is internal data exposure through server-side requests.

Technical view

The issue is an SSRF flaw in ssrf-agent’s defaultIpChecker. Improper validation of private IP addresses can allow outbound requests that should have been blocked. The CVSS 3.1 score is 6.5, with network attack vector, no privileges required, user interaction required, and high confidentiality impact.

Likely exposure

Exposure is likely limited to Node.js applications that depend on ssrf-agent before 1.0.5 and pass user-influenced URLs or hostnames into outbound request handling.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. The CVSS vector notes exploit code maturity as proof-of-concept, but no cited source here supports active exploitation in the wild.

Researcher notes

Focus analysis on call paths using ssrf-agent’s default IP checker and any URL-fetch features reachable by untrusted users. Evidence provided identifies the package and version boundary, but not affected applications beyond dependency usage.

Mitigation direction

  • Upgrade ssrf-agent to version 1.0.5 or later where used.
  • Check vendor advisories for affected downstream products, including NetApp guidance.
  • Restrict outbound server requests to approved destinations where feasible.
  • Add layered SSRF controls around private and internal network ranges.

Validation and detection

  • Search package manifests and lockfiles for ssrf-agent versions below 1.0.5.
  • Identify services where users can influence outbound request URLs or hostnames.
  • Review transitive dependencies that may include vulnerable ssrf-agent versions.
  • Confirm request filtering blocks private IP destinations after DNS resolution.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

description · low confidence lookup

Cloud metadata behavior lookup

The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-23718 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:P

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:P2.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2021-23718Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/assrf-agentunspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.