Description
Axel Download Accelerator 2.17.14 and earlier performs URL percent-decoding (http_decode()) on the output filename after the URL has been parsed and the filename component extracted. This allows an attacker to embed %2e%2e%2f (URL-encoded ../) sequences in the URL path. These sequences survive the URL parser intact (they contain no literal / characters) but are decoded into directory traversal sequences before the output file is opened for writing. As a result, a crafted URL can cause axel to write downloaded content to arbitrary filesystem paths relative to the current working directory.
References4
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H - CVSS 4.0
-
7.0
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 47 · as of 3 November 2026
- CWE
- CWE-24
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