Executive brief
Kyverno, a policy management tool for Kubernetes, enables legacy and weak 3DES cipher suites on its TLS endpoints. These deprecated ciphers are vulnerable to cryptanalytic attacks (Sweet32) that could allow attackers to recover small amounts of encrypted data over long-lived connections with high traffic volumes. This primarily affects administrators managing container security policies and could weaken the security of communications with Kyverno services.
Technical details
Kyverno versions 1.9.4 and earlier support insecure 3DES cipher suites (TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA and TLS_RSA_WITH_3DES_EDE_CBC_SHA) on TLS endpoints. These 64-bit block ciphers are vulnerable to the Sweet32 attack (CVE-2016-2183), a plaintext recovery attack that requires long-lived TLS connections carrying large volumes of traffic. The vulnerability is a weak cryptographic configuration issue rather than a protocol flaw. The issue is fixed in Kyverno 1.9.5 and 1.10.0. No exploitation in the wild is known.
Affected products
- Kyverno Kyverno ≤1.9.4
Timeline
- 2023-05-29: disclosed
- 2023: patched: Fixed in Kyverno 1.9.5 and 1.10.0