Limited directory traversal vulnerability on Windows in golang.org/x/crypto
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.6%
exploitation probability
0.6%top 51% of all CVEs
observed exploitation
nono source reports it
httpTokenCacheKey uses path.Base to extract the expected HTTP-01 token value to lookup in the DirCache implementation. On Windows, path.Base acts differently to filepath.Base, since Windows uses a different path separator (\ vs. /), allowing a user to provide a relative path, i.e. .well-known/acme-challenge/..\..\asd becomes ..\..\asd. The extracted path is then suffixed with +http-01, joined with the cache directory, and opened. Since the controlled path is suffixed with +http-01 before opening, the impact of this is significantly limited, since it only allows reading arbitrary files on the system if and only if they have this suffix.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
golang.org/x/crypto · golang.org/x/crypto/acme/autocert