What happened
curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say `https://`), accessed using a second, different, proxy
Affected versions
curl: 7.14.1 through before 8.14.2 (semver); 8.15.0 through before 8.16.1 (semver); 8.17.0 through before 8.20.0 (semver); 3b60bb725913ce7339aefef0a14b12df4c24db60 through before 188c2f166a20fa97c2325b2da7d0e5cecc13725f (git); 8.19.0; 8.18.0; 8.17.0; 8.16.0; 8.15.0; 8.14.1; 8.14.0; 8.13.0; 8.12.1; 8.12.0; 8.11.1; 8.11.0; 8.10.1; 8.10.0; 8.9.1; 8.9.0; 8.8.0; 8.7.1; 8.7.0; 8.6.0; 8.5.0; 8.4.0; 8.3.0; 8.2.1; 8.2.0; 8.1.2; 8.1.1; 8.1.0; 8.0.1; 8.0.0; 7.88.1; 7.88.0; 7.87.0; 7.86.0; 7.85.0; 7.84.0; 7.83.1; 7.83.0; 7.82.0; 7.81.0; 7.80.0; 7.79.1; 7.79.0; 7.78.0; 7.77.0; 7.76.1; 7.76.0; 7.75.0; 7.74.0; 7.73.0; 7.72.0; 7.71.1; 7.71.0; 7.70.0; 7.69.1; 7.69.0; 7.68.0; 7.67.0; 7.66.0; 7.65.3; 7.65.2; 7.65.1; 7.65.0; 7.64.1; 7.64.0; 7.63.0; 7.62.0; 7.61.1; 7.61.0; 7.60.0; 7.59.0; 7.58.0; 7.57.0; 7.56.1; 7.56.0; 7.55.1; 7.55.0; 7.54.1; 7.54.0; 7.53.1; 7.53.0; 7.52.1; 7.52.0; 7.51.0; 7.50.3; 7.50.2; 7.50.1; 7.50.0; 7.49.1; 7.49.0; 7.48.0; 7.47.1; 7.47.0; 7.46.0; 7.45.0; 7.44.0; 7.43.0; 7.42.1; 7.42.0; 7.41.0; 7.40.0; 7.39.0; 7.38.0; 7.37.1; 7.37.0; 7.36.0; 7.35.0; 7.34.0; 7.33.0; 7.32.0; 7.31.0; 7.30.0; 7.29.0; 7.28.1; 7.28.0; 7.27.0; 7.26.0; 7.25.0; 7.24.0; 7.23.1; 7.23.0; 7.22.0; 7.21.7; 7.21.6; 7.21.5; 7.21.4; 7.21.3; 7.21.2; 7.21.1; 7.21.0; 7.20.1; 7.20.0; 7.19.7; 7.19.6; 7.19.5; 7.19.4; 7.19.3; 7.19.2; 7.19.1; 7.19.0; 7.18.2; 7.18.1; 7.18.0; 7.17.1; 7.17.0; 7.16.4; 7.16.3; 7.16.2; 7.16.1; 7.16.0; 7.15.5; 7.15.4; 7.15.3; 7.15.2; 7.15.1; 7.15.0; 7.14.1 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.