CVE-2021-22918
Description
A flaw has been found in libuv. Node.js is vulnerable to out-of-bounds read in libuv's uv__idna_toascii() function which is used to convert strings to ASCII which is called by Node's DNS module's lookup() function and can lead to information disclosures or crashes. The highest threat from this vulnerability is to system availability.
Statement
As distributed by Red Hat, a maximum of 3 bytes out of bound can be read. This would not be sufficient to crash nodejs or other applications using libuv, unless it was recompiled using an address sanitizer. The memory disclosure is also very limited.
Red Hat Quay version 3.5 does not ship nodejs. Red Hat Quay version 3.4 consumes the nodejs from RHEL, so security tracking is provided by the container health index on the customer portal [1]. Additionally there is no impact from this issue on Quay 3.3 and 3.2 because they don't use nodejs as a HTTP server. [1] https://catalog.redhat.com/software/containers/quay/quay-rhel8/600e03aadd19c7786c43ae49?container-tabs=security
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 | 5.3 | 5.3 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Red Hat CVSS v3 Score Explanation
The flaws allows only for a maximum of 3 Out of Bounds bytes to be read. Using normal, default, compilation options (glibc, no memory sanitizer), this would not be sufficient to crash an application build on libuv (including node.js). Therefore Red Hat does not consider a loss of availability.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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