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CVE-2026-44323 medium CVSS 4.3

Vulnerability in github.com/free5gc/udr (CVE-2026-44323)

Summary

Vulnerability in github.com/free5gc/udr (CVE-2026-44323). Risk of unauthorized operations or information disclosure. Exploitable via DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript. Mitigation: upgrade to 1.4.3 or later.

Original description

The description as published by the source.

Summary

free5GC's UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler contains a nil-pointer dereference reachable from a single authenticated request, after one preparatory authenticated EE-subscription create. The handler checks _, ok = UESubsData.EeSubscriptionCollection[subsId] and sets a 404 problem-details on the miss path, but then continues to UESubsData.EeSubscriptionCollection[subsId].AmfSubscriptionInfos -- dereferencing the same missing entry instead of returning. Gin recovery converts the panic into HTTP 500, but the endpoint remains repeatedly panicable.

This endpoint requires a valid nudr-dr OAuth2 access token (i.e. PR:L, NOT PR:N), so this is scored as an authenticated panic-DoS, not as an unauth-bypass finding.

Details

Validated against the UDR container in the official Docker compose lab.

  • Source repo tag: v4.2.1
  • Running Docker image: free5gc/udr:v4.2.1
  • Runtime UDR commit: 754d23b0
  • Docker validation date: 2026-03-22
  • UDR endpoint: http://10.100.200.11:8000

Precondition (one authenticated EE-subscription create allocates UE state):

if !ok {
    udrSelf.UESubsCollection.Store(ueId, new(udr_context.UESubsData))
    value, _ = udrSelf.UESubsCollection.Load(ueId)
}
...
UESubsData.EeSubscriptionCollection[newSubscriptionID] = new(udr_context.EeSubscriptionCollection)

Vulnerable handler (delete on amf-subscriptions): the ok miss path sets pd but doe…

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-44323 has been found in github.com/free5gc/udr.
Attackers can target a specific entry point like DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade github.com/free5gc/udr to 1.4.3 or later.
If unsure, ask your IT team or search "github.com/free5gc/udr CVE-2026-44323" on the vendor's site.

CVE-2026-44323 (github.com/free5gc/udr) — CWE-476 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript / subsId / UESubsCollection / RemoveAmfSubscriptionsInfoProcedure
Patched: 1.4.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-476) exists in github.com/free5gc/udr. Attackers reach the vulnerable code path via DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/free5gc/udr. Attack surface: DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript / subsId / UESubsCollection / RemoveAmfSubscriptionsInfoProcedure.

🔥 Severity

Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.4.3.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/free5gc/udr' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'github.com/free5gc/udr' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で github.com/free5gc/udr を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply patch patch 
    Upgrade github.com/free5gc/udr to 1.4.3

    ステージング環境で 1.4.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。

  4. 4
    Post-deployment verification verify 
    Replay attack against DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscript on staging to confirm patch closes the vector

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

go github.com/free5gc/udr
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.4.3"}]}]

References

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