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GHSA-f8mr-jv2c-v8mg

HighCVSS 8.7 / 10
Published Sep 9, 2020·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

Impact

The Python TUF reference implementation tuf<0.12 will incorrectly trust a previously downloaded root metadata file which failed verification at download time. This allows an attacker who is able to serve multiple new versions of root metadata (i.e. by a man-in-the-middle attack) culminating in a version which has not been correctly signed to control the trust chain for future updates.

While investigating the reported vulnerability, we discovered that the detailed client workflow was not fully implemented. Specifically, for step 1.3 the newly downloaded root metadata was not being verified with a threshold of keys specified in the new root metadata file. This missing step of the client workflow has been implemented in PR #1101, which is included in v0.14.0 of tuf.

Patches

A fix, is available in version 0.12 and newer.

Workarounds

No workarounds are known for this issue.

References

  • Pull request resolving the invalid root becoming trusted issue PR 885
  • Pull request implementing self verification of newly downloaded root metadata PR 1101
Risk Scores
Base Score
8.7

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.

Threat Intelligence
8.0

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.67%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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