CVE-2024-55655

CVE-2024-55655 is a low-severity vulnerability with a CVSS 4.0 base score of 2.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

sigstore-python is a Python tool for generating and verifying Sigstore signatures. Versions of sigstore-python newer than 2.0.0 but prior to 3.6.0 perform insufficient validation of the "integration time" present in "v2" and "v3" bundles during the verification flow: the "integration time" is verified *if* a source of signed time (such as an inclusion promise) is present, but is otherwise trusted if no source of signed time is present. This does not affect "v1" bundles, as the "v1" bundle format always requires an inclusion promise. Sigstore uses signed time to support verification of signatures made against short-lived signing keys. The impact and severity of this weakness is *low*, as Sigstore contains multiple other enforcing components that prevent an attacker who modifies the integration timestamp within a bundle from impersonating a valid signature. In particular, an attacker who modifies the integration timestamp can induce a Denial of Service, but in no different manner than already possible with bundle access (e.g. modifying the signature itself such that it fails to verify). Separately, an attacker could upload a *new* entry to the transparency service, and substitute their new entry's time. However, this would still be rejected at validation time, as the new entry's (valid) signed time would be outside the validity window of the original signing certificate and would nonetheless render the attacker auditable.

Frequently asked questions

What is CVE-2024-55655?
sigstore-python is a Python tool for generating and verifying Sigstore signatures. Versions of sigstore-python newer than 2.0.0 but prior to 3.6.0 perform insufficient validation of the "integration time" present in "v2" and "v3" bundles during the verification flow: the "integration time" is verified *if* a source of signed time (such as an inclusion promise) is present, but is otherwise trusted if no source of signed time is present. This does not affect "v1" bundles, as the "v1" bundle format always requires an inclusion promise. Sigstore uses signed time to support verification of signatures made against short-lived signing keys. The impact and severity of this weakness is *low*, as Sigstore contains multiple other enforcing components that prevent an attacker who modifies the integration timestamp within a bundle from impersonating a valid signature. In particular, an attacker who modifies the integration timestamp can induce a Denial of Service, but in no different manner than already possible with bundle access (e.g. modifying the signature itself such that it fails to verify). Separately, an attacker could upload a *new* entry to the transparency service, and substitute their new entry's time. However, this would still be rejected at validation time, as the new entry's (valid) signed time would be outside the validity window of the original signing certificate and would nonetheless render the attacker auditable.
How severe is CVE-2024-55655?
CVE-2024-55655 has a CVSS 4.0 base score of 2.7, rated low severity.
Is CVE-2024-55655 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2024-55655?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-55655 have an EU (EUVD) identifier?
Yes. CVE-2024-55655 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-3479.
When was CVE-2024-55655 published?
CVE-2024-55655 was published on 2024-12-10 and last updated on 2026-06-17.

References

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