RMAC revert to the beginning of the session in libosdp
libosdp is an implementation of IEC 60839-11-5 OSDP (Open Supervised Device Protocol) and provides a C library with support for C++, Rust and Python3. In affected versions an unexpected `REPLY_CCRYPT` or `REPLY_RMAC_I` may be introduced into an active stream when they should not be. 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 reader) Once attacker captures a session with the message to be replayed, he stops resetting the connection and waits for signal to perform the replay to of the PD to CP message (ex: by signaling remotely 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 beginning of the session. At that phase - attacker can replay all the messages from the beginning of the session. This issue has been addressed in commit `298576d9` which is included in release version 3.0.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Published
- Nov 11, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 2th percentile
- CWE
- CWE-924
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Report tools
Action score
20
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 5.1
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
goToMain libosdp
- < 3.0.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| PyPI | libosdp | before 3.0.0 | 3.0.0 |
Same product
gotomain: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-52296libosdp has a null pointer deref in osdp_reply_name26Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| PyPI:libosdp | 3.0.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-924 · Improper Enforcement of Message Integrity During Transmission in a Communication ChannelCVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/goToMain/libosdp/commit/298576d9214b48214092eebdd892ec77be085e5a
- github.com/goToMain/libosdp/security/advisories/GHSA-xhjw-7vh5-qxqm
Vendor advisories and official records. Exploit/PoC links are deliberately left out.