CVE-2023-53769
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: virt/coco/sev-guest: Double-buffer messages The encryption algorithms read and write directly to shared unencrypted memory, which may leak information as well as permit the host to tamper with the message integrity. Instead, copy whole messages in or out as needed before doing any computation on them.
Statement
This vulnerability is rated as Moderate by Red Hat. The vulnerability primarily impacts confidentiality and integrity, because plaintext or intermediate values can be observed via shared unencrypted memory and as such there can be host-controlled modifications of the message buffer that can influence what is encrypted or verified and decrypted. Impact on availability is limited to tampering causing request failures or EBADMSG errors. However, triggering this vulnerability most likely requires elevated privileges that correspond to hypervisor or host-level control (typically higher than what a guest local user will possess).
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 | 6 | N/A | 9.3 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | High | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Changed |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | Low | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:L
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality
Technical Impact: Read Application Data; Modify Files or Directories
Anyone can read the information by gaining access to the channel being used for communication. Many communication channels can be "sniffed" (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data.
Integrity,Confidentiality
Technical Impact: Read Application Data; Modify Files or Directories; Other
When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to "sniff" the cleartext from the recorded communications in the dump itself. Even if the information is encoded in a way that is not human-readable, certain techniques could determine which encoding is being used, then decode the information.
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