LibOSDP RMAC revert to the beginning of the sessionGHSA-xhjw-7vh5-qxqm
MEDIUMFix: goToMain/libosdp@298576dGHSA-xhjw-7vh5-qxqm is a medium-severity (CVSS 5.1) CWE-924 vulnerability in libosdp. A fix is available for libosdp — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xhjw-7vh5-qxqm.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-xhjw-7vh5-qxqm by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 388,997 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
libosdpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
- Issues:
- SCS_14 is allowed on encrypted connection (osdp_phy.c)
- No validation for RMAC_I is only in response to osdp_SCRYPT (osdp_cp.c)
- Couldn't find anything specific in the OSDP specifications indicating it is forbidden, I'm gussing it shouldn't be allowed according from the secure connection initialization flow (let me know if you think there is spec-rela ted change that should be done)
- Attack:
- Once RMAC_I message can be sent during a session, attacker with MITM access to the communication may intercept the original RMAC_I reply and save it.
- While the session continues, the attacker will record all of the replies and save them, till capturing the message to be replied (can be detected by ID, length or time based on inspection of visual activity next to the reade r)
- Once attacker captures a session with the message to be replayed, he stops reseting the connection and waits for signal to perform the replay to of the PD to CP message (ex: by signaling remotly to the MIMT device or setting a specific timing).
- in order to replay, the attacker will craft a specific RMAC_I message in the proper seq of the execution, which will result in reverting the RMAC to the begining of the session.
- At that phase - attacker can replay all the messages from the begining of the session.
Impact
Replay attack
Patches
This issue has been fixed in 298576d9214b48214092eebdd892ec77be085e5a
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | libosdp | all versions | 3.0.0pip install --upgrade 'libosdp==3.0.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for libosdp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update libosdp to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xhjw-7vh5-qxqm is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-xhjw-7vh5-qxqm in your dependencies?
Find it across PyPI, including transitive dependencies.