Bug 2569525 - CVE-2026-124747 busybox: Heap buffer overflow in wget FTP resume when the resume offset exceeds the reported file size [epel-all]
Summary: CVE-2026-124747 busybox: Heap buffer overflow in wget FTP resume when the res...
Keywords:
Status: NEW
Alias: None
Product: Fedora EPEL
Classification: Fedora
Component: busybox
Version: epel10
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Tom "spot" Callaway
QA Contact:
URL:
Whiteboard: {"flaws": ["6f730170-2749-47b0-9864-4...
Depends On:
Blocks: CVE-2026-124747
TreeView+ depends on / blocked
 
Reported: 2026-11-10 12:45 UTC by Vladimir Vasilev
Modified: 2026-11-10 12:45 UTC (History)
6 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


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Description Vladimir Vasilev 2026-11-10 12:45:09 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A flaw was found in BusyBox wget. When resuming an FTP download, prepare_ftp_session() in networking/wget.c subtracts the resume offset from the file size reported by the server without validating that the offset does not exceed it, allowing the content_len variable to become negative. In retrieve_file_data(), a (int) cast lets a negative content_len whose low 32 bits are positive pass the length check, and the truncated value is then used as the fread() size into the heap-allocated wget buffer. A malicious FTP server, or an on-path attacker when plain FTP is used, can trigger this when wget resumes a download whose offset is more than 2 GiB larger than the reported file size, overwriting heap memory beyond the buffer with server-controlled data, which may lead to a crash or potentially code execution.


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