CVE-2018-1000159 tlslite-ng off-by-one error on mac checking
An attacker can manipulate TLS ciphertext without detection due to improper integrity check validation in tlslite-ng.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-1000159?
CVE-2018-1000159 is a medium-severity vulnerability in n/a, published on 18 Apr 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
tlslite-ng version 0.7.3 and earlier, since commit d7b288316bca7bcdd082e6ccff5491e241305233 contains a CWE-354: Improper Validation of Integrity Check Value vulnerability in TLS implementation, tlslite/utils/constanttime.py: ct_check_cbc_mac_and_pad(); line "end_pos = data_len - 1 - mac.digest_size" that can result in an attacker manipulating the TLS ciphertext which will not be detected by receiving tlslite-ng. This attack appears to be exploitable via man in the middle on a network connection. This vulnerability appears to have been fixed after commit 3674815d1b0f7484454995e2737a352e0a6a93d8.
Weakness: CWE-354
Which versions are affected by CVE-2018-1000159?
3 open source packages ship an affected version, including tlslite-ng. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tlslite-ng PyPI | All versions | 0.7.4 |
tlslite-ng PyPI | All versions | 0.7.4 |
tlslite-ng PyPI | All versions | 0.7.4 |
Products include Tlslite-Ng Project Tlslite-Ng.
How do I fix CVE-2018-1000159?
Upgrade tlslite-ng to 0.7.4 or later.
Is CVE-2018-1000159 being exploited?
There is no known exploitation of CVE-2018-1000159 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-cwh5-3cw7-4286, PYSEC-2018-31, UBUNTU-CVE-2018-1000159.