libspdm: Improper Authentication
CVE-2023-31127 is a high-severity improper authentication vulnerability in libspdm from DMTF, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected libspdm versions: < 2.3.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.94% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of libspdm you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.0 | Critical | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
libspdm is a sample implementation that follows the DMTF SPDM specifications. A vulnerability has been identified in SPDM session establishment in libspdm prior to version 2.3.1. If a device supports both DHE session and PSK session with mutual authentication, the attacker may be able to establish the session with `KEY_EXCHANGE` and `PSK_FINISH` to bypass the mutual authentication. This is most likely to happen when the Requester begins a session using one method (DHE, for example) and then uses the other method's finish (PSK_FINISH in this example) to establish the session. The session hashes would be expected to fail in this case, but the condition was not detected. This issue only impacts the SPDM responder, which supports `KEY_EX_CAP=1 and `PSK_CAP=10b` at same time with mutual authentication requirement. The SPDM requester is not impacted. The SPDM responder is not impacted if `KEY_EX_CAP=0` or `PSK_CAP=0` or `PSK_CAP=01b`. The SPDM responder is not impacted if mutual authentication is not required. libspdm 1.0, 2.0, 2.1, 2.2, 2.3 are all impacted. Older branches are not maintained, but users of the 2.3 branch may receive a patch in version 2.3.2. The SPDM specification (DSP0274) does not contain this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in libspdm
- 7.5 High severity
Recent Improper Authentication vulnerabilities
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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