Red Hat Enterprise Linux 8 update for the httpd:2.4 module
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2021-26691 CVE-2021-40438 |
| CWE-ID | CWE-476 CWE-918 |
| Exploitation vector | Network |
| Public exploit | Vulnerability #2 is being exploited in the wild. |
| Vulnerable software |
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server - TUS Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux Server - AUS Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux for ARM 64 - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux for ARM 64 Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 Operating systems & Components / Operating system |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) NULL pointer dereference
EUVDB-ID: #VU53776
Risk: Low
CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2021-26691
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in mod_session. A a malicious backend server or SessionHeader can trigger a denial of service (DoS) condition.
MitigationInstall updates from vendor's website.
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 8.4
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.4
Red Hat Enterprise Linux Server - TUS: 8.4
Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.4
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.4
Red Hat Enterprise Linux Server - AUS: 8.4
Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.4
Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.4
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
CPE2.3- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_for_ibm_power_le_-_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
https://access.redhat.com/errata/RHSA-2021:3816
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Server-Side Request Forgery (SSRF)
EUVDB-ID: #VU56678
Risk: High
CVSSv4.0: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:N/SA:N/E:A/U:Amber]
CVE-ID: CVE-2021-40438
CWE-ID:
CWE-918 - Server-Side Request Forgery (SSRF)
Exploit availability: Yes
DescriptionThe disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input within the mod_proxy module in Apache HTTP Server. A remote attacker can send a specially crafted HTTP request with a chosen uri-path and trick the web server to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.
MitigationInstall updates from vendor's website.
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 8.4
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.4
Red Hat Enterprise Linux Server - TUS: 8.4
Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.4
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.4
Red Hat Enterprise Linux Server - AUS: 8.4
Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.4
Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.4
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
CPE2.3- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_for_ibm_power_le_-_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
https://access.redhat.com/errata/RHSA-2021:3816
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
Yes. This vulnerability is being exploited in the wild.
