SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-40438

Apache HTTP Server-Side Request Forgery (SSRF)

KEVCRITICAL 9.0EPSS 100.0%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 15 December 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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.

CVSS 3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS
100.00% probability · 100th percentile
CISA KEV
Listed 1 December 2021 · due 15 December 2021 · used in ransomware campaigns
Weakness
CWE-918
Affected
resf/rocky linux · redhat/enterprise linux · redhat/enterprise linux eus · redhat/enterprise linux for arm 64 · redhat/enterprise linux for arm 64 eus · redhat/enterprise linux for ibm z systems · redhat/enterprise linux for ibm z systems eus · redhat/enterprise linux for ibm z systems eus s390x · redhat/enterprise linux for power big endian · redhat/enterprise linux for power little endian · redhat/enterprise linux for power little endian eus · redhat/enterprise linux for scientific computing · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server for power little endian update services for sap solutions · redhat/enterprise linux server tus · redhat/enterprise linux server update services for sap solutions · redhat/enterprise linux update services for sap solutions · redhat/enterprise linux workstation · redhat/jboss core services · +19 more
Source
security@apache.org

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-40438

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.