How severe is GHSA-hw43-fcmm-3m5g?

GHSA-hw43-fcmm-3m5g has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-hw43-fcmm-3m5g?

GHSA-hw43-fcmm-3m5g affects the following packages: gov.nsa.emissary:emissary (Maven). Ecosystems affected: Maven.

How do I fix GHSA-hw43-fcmm-3m5g?

Update gov.nsa.emissary:emissary to 8.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hw43-fcmm-3m5g is resolved across your whole dependency graph.

How do I detect GHSA-hw43-fcmm-3m5g in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gov.nsa.emissary:emissary. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-hw43-fcmm-3m5g if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against GHSA-hw43-fcmm-3m5g?

O3 pinpoints whether GHSA-hw43-fcmm-3m5g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-hw43-fcmm-3m5g actively exploited in the wild?

No public exploit code has been indexed for GHSA-hw43-fcmm-3m5g yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-hw43-fcmm-3m5g?

GHSA-hw43-fcmm-3m5g has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 9th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-hw43-fcmm-3m5g published, and has it been updated?

GHSA-hw43-fcmm-3m5g was published on March 5, 2025 and was last updated on March 6, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

GHSA-hw43-fcmm-3m5g

HIGH

Emissary May Use a Broken or Risky Cryptographic Algorithm

Also known asCVE-2025-27508

Published

Mar 5, 2025

Updated

Mar 6, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk9th percentile+0.06%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

☕gov.nsa.emissary:emissary

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The ChecksumCalculator class within allows for hashing and checksum generation, but it includes or defaults to algorithms that are no longer recommended for secure cryptographic use cases (e.g., SHA-1, CRC32, and SSDEEP). These algorithms, while possibly valid for certain non-security-critical tasks, can expose users to security risks if used in scenarios where strong cryptographic guarantees are required.

Requirement from NIST

Requirement from NIST regarding SHA1

https://csrc.nist.gov/projects/hash-functions#:~:text=NIST%20deprecated%20the%20use%20of,use%20of%20the%20SHA%2D1.

Federal agencies should use SHA-2 or SHA-3 as an alternative to SHA-1. Further guidance will be available soon. Send questions on the transition to [email protected].

https://www.nist.gov/news-events/news/2022/12/nist-retires-sha-1-cryptographic-algorithm

Mitigation and Fix

Make it clear to developers and users that the ChecksumCalculator is specific to the "Known File Filter" (KFF) document similarity feature and is not intended to suggest or endorse global use as a cryptographically secure hashing or checksum mechanism.

While these specific default insecure algorithms can not be updated without violating the intended use-case, it can be clearly documented and prevented using better access modifiers in the ChecksumCalculator class.

Details

Within ChecksumCalculator.java, the following points raise potential security concerns:

SHA-1: SHA-1 has been widely deprecated for cryptographic purposes due to known collision attacks. The constructor defaults to "SHA-1" if no specific algorithm is provided. CRC32: CRC32 is a simple checksum mechanism, not a cryptographic hash function. It is unsuitable for security-critical integrity checks since it can be easily manipulated or collided. SSDEEP (Fuzzy Hashing): SSDEEP is a context-specific tool used for similarity matching and may not be a secure cryptographic function for authentication or tamper detection. There is no apparent mechanism to prevent developers from using these weaker algorithms in security-sensitive contexts. Users of emissary who rely on ChecksumCalculator for strong security guarantees (e.g., data integrity or authentication) may be misled into assuming these algorithms provide adequate protection.

PoC

Code could be found https://github.com/NationalSecurityAgency/emissary/blob/main/src/main/java/emissary/kff/ChecksumCalculator.java

Impact

Impact Weakened Security Posture: Applications integrating Emissary may inadvertently use these algorithms in a way that could be exploited (e.g., collisions in SHA-1, trivial collisions in CRC32). Misleading Assurance: Developers might assume Emissary’s recommended defaults are secure for cryptographic validation, which can result in insecure implementations. Potential for Collision Attacks: Attackers could craft inputs that yield the same SHA-1 hash or manipulate CRC32 sums, thus bypassing naive integrity checks. Because this project is produced under the NSA umbrella, users may have an inflated trust in its security posture, potentially leading them to rely on these algorithms in high-security environments without recognizing the associated risks.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`gov.nsa.emissary:emissary`	all versions	8.24.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gov.nsa.emissary:emissary. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update gov.nsa.emissary:emissary to 8.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hw43-fcmm-3m5g 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.
How O3 protects you
O3 pinpoints whether GHSA-hw43-fcmm-3m5g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-hw43-fcmm-3m5g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The ChecksumCalculator class within allows for hashing and checksum generation, but it includes or defaults to algorithms that are no longer recommended for secure cryptographic use cases (e.g., SHA-1, CRC32, and SSDEEP). These algorithms, while possibly valid for certain non-security-critical tasks, can expose users to security risks if used in scenarios where strong cryptographic guarantees are required. ### Requirement from NIST Requirement from NIST regarding SHA1 https://csrc.nist.gov/projects/hash-functions#:~:text=NIST%20deprecated%20the%20use%20of,use%20of%20the%20SHA%2D

O3 Security · Impact-Aware SCA

Is GHSA-hw43-fcmm-3m5g in your dependencies?

O3 detects GHSA-hw43-fcmm-3m5g across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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