CVE-2021-38575
Description
A flaw was found in edk2. Missing checks in the IScsiHexToBin function in NetworkPkg/IScsiDxe lead to a buffer overflow allowing a remote attacker, who can inject himself in the communication between edk2 and the iSCSI target, to write arbitrary data to any address in the edk2 firmware and potentially execute code. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | 8.1 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
To trigger this flaw an attacker has to do a Man-in-the-middle attack and modify/inject packets in the communication between the target and the initiator (edk2) or he has to control the target used by the configured firmware (e.g. compromising the server). For these reasons, Attack Complexity is set to High (AC:H).
Acknowledgements
This issue was discovered by Laszlo Ersek (Red Hat).
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