Back to the CVE list
CVE-2021-40438 CISA KEV · Actively exploitedLinked to ransomwareSuited to automated attack · CISA

mod_proxy SSRF

CVSS score

9.0

EPSS probability

%100.0

Risk score

18.0

Published

5 y ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

DayBreach CVE AI Research

CVE-2021-40438 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2021-40438 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1Apache Software FoundationApache HTTP Server View
2resfrocky linux View
3redhatenterprise linux View
4redhatenterprise linux eus View
5redhatenterprise linux eus View
6redhatenterprise linux eus View
7redhatenterprise linux eus View
8redhatenterprise linux eus View
9redhatenterprise linux for arm 64 View
10redhatenterprise linux for arm 64 eus View
11redhatenterprise linux for arm 64 eus View
12redhatenterprise linux for ibm z systems View
13redhatenterprise linux for ibm z systems View
14redhatenterprise linux for ibm z systems eus View
15redhatenterprise linux for ibm z systems eus View
16redhatenterprise linux for ibm z systems eus View
17redhatenterprise linux for ibm z systems eus s390x View
18redhatenterprise linux for power big endian View
19redhatenterprise linux for power little endian View
20redhatenterprise linux for power little endian View
21redhatenterprise linux for power little endian eus View
22redhatenterprise linux for power little endian eus View
23redhatenterprise linux for power little endian eus View
24redhatenterprise linux for power little endian eus View
25redhatenterprise linux for power little endian eus View
26redhatenterprise linux for scientific computing View
27redhatenterprise linux server View
28redhatenterprise linux server aus View
29redhatenterprise linux server aus View
30redhatenterprise linux server aus View
31redhatenterprise linux server aus View
32redhatenterprise linux server aus View
33redhatenterprise linux server aus View
34redhatenterprise linux server aus View
35redhatenterprise linux server aus View
36redhatenterprise linux server for power little endian update services for sap solutions View
37redhatenterprise linux server for power little endian update services for sap solutions View
38redhatenterprise linux server for power little endian update services for sap solutions View
39redhatenterprise linux server for power little endian update services for sap solutions View
40redhatenterprise linux server for power little endian update services for sap solutions View
41redhatenterprise linux server for power little endian update services for sap solutions View
42redhatenterprise linux server for power little endian update services for sap solutions View
43redhatenterprise linux server tus View
44redhatenterprise linux server tus View
45redhatenterprise linux server tus View
46redhatenterprise linux server tus View
47redhatenterprise linux server tus View
48redhatenterprise linux server tus View
49redhatenterprise linux server update services for sap solutions View
50redhatenterprise linux server update services for sap solutions View
51redhatenterprise linux update services for sap solutions View
52redhatenterprise linux update services for sap solutions View
53redhatenterprise linux update services for sap solutions View
54redhatenterprise linux update services for sap solutions View
55redhatenterprise linux update services for sap solutions View
56redhatenterprise linux workstation View
57redhatjboss core services View
58redhatenterprise linux View
59redhatsoftware collections View
60redhatenterprise linux server workstation View
61apachehttp server View
62fedoraprojectfedora View
63fedoraprojectfedora View
64debiandebian linux View
65debiandebian linux View
66debiandebian linux View
67netappcloud backup View
68netappclustered data ontap View
69netappstoragegrid View
70broadcombrocade fabric operating system firmware View
71f5f5os View
72f5f5os View
73oracleenterprise manager ops center View
74oraclehttp server View
75oraclehttp server View
76oracleinstantis enterprisetrack View
77oracleinstantis enterprisetrack View
78oracleinstantis enterprisetrack View
79oraclesecure global desktop View
80oraclezfs storage appliance kit View
81siemensruggedcom nms View
82siemenssinec nms View
83siemenssinema remote connect server View
84siemenssinema remote connect server View
85siemenssinema server View
86tenabletenable.sc View
Total affected vendors: 12|Products: 86

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
9.0CVSS V31CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HNVD
9.0CVSS V3_1CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HCVE ADP
6.8CVSS V2—AV:N/AC:M/Au:N/C:P/I:P/A:PNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
canonical

Apply updates per vendor instructions.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

This CVE is marked as actively exploited in the CISA KEV catalogue, but no verified, downloadable public PoC or Metasploit module has been found yet. Evidence of active exploitation does not mean that public exploit code exists.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-40438 is associated with the following CWEs:

CWE-918: Server-Side Request Forgery (SSRF)

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-40438 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

https://httpd.apache.org/security/vulnerabilities_24.htmlvendor-advisoryFEDORA-2021-dce7e7738evendor-advisory[httpd-users] 20210923 [users@httpd] 2.4.49 security fixes: more infovendor-advisory[httpd-users] 20210923 Re: [users@httpd] 2.4.49 security fixes: more infovendor-advisory[httpd-users] 20210923 [users@httpd] Re: [External] : [users@httpd] 2.4.49 security fixes: more infovendor-advisory[httpd-users] 20210923 Re: [users@httpd] Re: [External] : [users@httpd] 2.4.49 security fixes: more infovendor-advisoryFEDORA-2021-e3f6dd670dvendor-advisory[debian-lts-announce] 20211002 [SECURITY] [DLA 2776-1] apache2 security updatevendor-advisory[httpd-bugs] 20211008 [Bug 65616] CVE-2021-36160 regressionvendor-advisoryDSA-4982vendor-advisory

CVSS Vector Radar Chart

9.0 / 10
Attack VectorNetworkComplexityHighPrivilegesNoneUser Interact.NoneConfidentialityHighIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)High
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

AS
Apache Software Foundation logo
Apache Software Foundation
R
resf logo
resf
R
redhat logo
redhat
A
apache logo
apache
F
fedoraproject logo
fedoraproject
D
debian logo
debian

Weakness Type (CWE & CAPEC)

CWE-918

Similar Vulnerabilities

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free keyDocumentation
curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2021-40438"