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Back to active CVEs
High · CVSS 7.1CVE-2021-47366

afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS serverCVE-2021-47366

Answer in brief

CVE-2021-47366 records a High severity (CVSS 7.1) vulnerability in afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published May 21, 2024Updated Aug 5, 2026Source checked Nov 4, 2026First seen by HOL Aug 4, 2026Material review Aug 5, 2026
Upstream Advisory

Key facts

Risk
High · CVSS 7.1
Exploitation
Not marked as known exploited
Affected software
5 mapped packages or products
Fix availability
Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
ProductAffected versionsFixed versions
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*Not reportedNot reported
Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Linux/Linuxgeneric>=b9b1f8d5930a813879278d0cbfc8c658d6a038dc <e66fc460d6dcf85cf12288e133a081205aebcd97 || >=b9b1f8d5930a813879278d0cbfc8c658d6a038dc <b537a3c21775075395af475dcc6ef212fcf29db8e66fc460d6dcf85cf12288e133a081205aebcd97, b537a3c21775075395af475dcc6ef212fcf29db8
Linux/Linuxgeneric2.6.22Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
  2. 2Review the reported fix. Update Linux/Linux to e66fc460d6dcf85cf12288e133a081205aebcd97 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    May 21, 2024

    Evidence: source:cvelist:source_dates:source-dates:record
  2. Source modified

    Aug 5, 2026

    Evidence: source:cvelist:source_dates:source-dates:record
  3. First seen by HOL

    Aug 4, 2026

Sources and claim methodology

  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution VulnerabilityAlso CWE-787
  • Linksys E5600 JSON Request mesh_login.cgi strcpy out-of-bounds writeAlso CWE-787
  • Linksys E5600 Header upload_fw.cgi init_multipart out-of-bounds writeAlso CWE-787
  • Out-of-bounds Write in BootloaderAlso CWE-787

Record context

Vulnerability class
Memory Corruption
EPSS
Not reported
CWE IDs
CWE-787
Source
CVE List V5
Source checked
Nov 4, 2026
References
2 linked sources
Open source record