[Eclipse Milo] CVE Reservation Request: Basic128Rsa15 username-token padding oracle
# CVE Reservation Request
## CVE record information
**Project name:** Eclipse Milo
**Project id:** iot.milo
**Versions affected:** v0.6.0 through v1.1.4
**Common Weakness Enumeration (CWE):**
- [CWE-204: Observable Response Discrepancy](https://cwe.mitre.org/data/definitions/204.html)
**Common Attack Pattern Enumerations and Classifications (CAPEC):**
- [CAPEC-463: Padding Oracle Crypto Attack](https://capec.mitre.org/data/definitions/463.html)
**Common Vulnerability Scoring System:** [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N (9.1 Critical)](https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N)
**Summary:** In Eclipse Milo versions 0.6.0 through 1.1.4, username-token processing returns distinguishable errors for invalid RSA PKCS#1 v1.5 padding and other authentication failures, allowing an on-path attacker who captures a victim's `Basic128Rsa15`-encrypted username token to use repeated unauthenticated `ActivateSession` requests as a padding oracle, recover the victim's password, and authenticate with the recovered credentials.
**Links:**
- https://github.com/eclipse-milo/milo/commit/db59fae993a3a1bc66fffc8a2796d444b40285fb
- https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/598
**Credits:** Abhinav Agarwal (GitHub: @abhinavagarwal07)
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