CVE-2026-95105

Summary

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking vulnerability in danielberkompas cloak allows an attacker with write access to stored ciphertext to make it decrypt to a chosen value via bit flipping.

Cloak.Ciphers.AES.CTR encrypts with AES-256 in CTR mode and stores the key tag, the IV and the ciphertext with no MAC. decrypt/2 checks only the key tag and the minimum length before it returns the plaintext, and Cloak.Ciphers.Deprecated.AES.CTR decrypts the legacy format the same way. CTR is a stream cipher, so a value XORed into the stored ciphertext is XORed into the plaintext at the same offset. An attacker who can write to the encrypted store (for example through SQL injection or a compromised replica) and who knows or can guess a stored plaintext can replace it with any value of the same length. The application receives that value with no error.

This issue affects cloak: from 0.1.0-pre onward.

Affected Software

VendorProductVersion RangeStatus
danielberkompascloak0.1.0-pre < *affected
danielberkompascloak2bd17019e285b55c5c218cc842537bf9280f24c3 < *affected

Weaknesses

  • CWE-649: CWE-649 Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

Workarounds

Configure the vault with Cloak.Ciphers.AES.GCM as the default cipher and re-encrypt existing values, for example with the cloak.migrate.ecto task from cloak_ecto. Then remove Cloak.Ciphers.AES.CTR and Cloak.Ciphers.Deprecated.AES.CTR from the vault configuration, so that ciphertext in the CTR format is no longer decrypted. AES-GCM authenticates the ciphertext and rejects modified values.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References