CVE-2021-47366 Vulnerability Analysis & Exploit Details

CVE-2021-47366
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-47366 Details

Status: Awaiting Analysis

Last updated: 🕡 21 Nov 2024, 06:35 UTC
Originally published on: 🕒 21 May 2024, 15:15 UTC

Time between publication and last update: 183 days

CVSS Release:

CVE-2021-47366 Vulnerability Summary

CVE-2021-47366: In the Linux kernel, the following vulnerability has been resolved: afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and Linux's afs client switches between them when talking to a non-YFS server if the read size, the file position or the sum of the two have the upper 32 bits set of the 64-bit value. This is a problem, however, since the file position and length fields of FS.FetchData are *signed* 32-bit values. Fix this by capturing the capability bits obtained from the fileserver when it's sent an FS.GetCapabilities RPC, rather than just discarding them, and then picking out the VICED_CAPABILITY_64BITFILES flag. This can then be used to decide whether to use FS.FetchData or FS.FetchData64 - and also FS.StoreData or FS.StoreData64 - rather than using upper_32_bits() to switch on the parameter values. This capabilities flag could also be used to limit the maximum size of the file, but all servers must be checked for that. Note that the issue does not exist with FS.StoreData - that uses *unsigned* 32-bit values. It's also not a problem with Auristor servers as its YFS.FetchData64 op uses unsigned 64-bit values. This can be tested by cloning a git repo through an OpenAFS client to an OpenAFS server and then doing "git status" on it from a Linux afs client[1]. Provided the clone has a pack file that's in the 2G-4G range, the git status will show errors like: error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index This can be observed in the server's FileLog with something like the following appearing: Sun Aug 29 19:31:39 2021 SRXAFS_FetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001 Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: Pos 18446744071815340032, Len 3154 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: file size 2400758866 ... Sun Aug 29 19:31:40 2021 SRXAFS_FetchData returns 5 Note the file position of 18446744071815340032. This is the requested file position sign-extended.

Assessing the Risk of CVE-2021-47366

Access Complexity Graph

The exploitability of CVE-2021-47366 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2021-47366

No exploitability data is available for CVE-2021-47366.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2021-47366, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2021-47366, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2021-47366 does not compromise confidentiality.
  • Integrity: None
    CVE-2021-47366 does not impact data integrity.
  • Availability: None
    CVE-2021-47366 does not affect system availability.

Exploit Prediction Scoring System (EPSS)

The EPSS score estimates the probability that this vulnerability will be exploited in the near future.

EPSS Score: 0.043% (probability of exploit)

EPSS Percentile: 12.0% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 88.0% of others.

CVE-2021-47366 References

External References

CWE Common Weakness Enumeration

Unknown

Protect Your Infrastructure against CVE-2021-47366: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2025-31203 – An integer overflow was addressed with improved input validation. This issue is fixed in macOS Sequoia 15.4, tvOS 18.4, iPadOS 17.7.6, macOS Sonoma...
  • CVE-2025-31202 – A null pointer dereference was addressed with improved input validation. This issue is fixed in iOS 18.4 and iPadOS 18.4, macOS Sequoia 15.4, tvOS ...
  • CVE-2025-31197 – The issue was addressed with improved checks. This issue is fixed in macOS Sequoia 15.4, tvOS 18.4, macOS Ventura 13.7.5, iPadOS 17.7.6, macOS Sono...
  • CVE-2025-30445 – A type confusion issue was addressed with improved checks. This issue is fixed in macOS Sequoia 15.4, tvOS 18.4, macOS Ventura 13.7.5, iPadOS 17.7....
  • CVE-2025-24271 – An access issue was addressed with improved access restrictions. This issue is fixed in macOS Sequoia 15.4, tvOS 18.4, macOS Ventura 13.7.5, iPadOS...