Access control error in curl (Alpine package)
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2016-5420 |
| CWE-ID | CWE-285 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
curl (Alpine package) Operating systems & Components / Operating system package or component |
| Vendor | Alpine Linux Development Team |
Security Bulletin
This security bulletin contains one low risk vulnerability.
1) Improper Authorization
EUVDB-ID: #VU378
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2016-5420
CWE-ID:
CWE-285 - Improper Authorization
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to an error when handling client TLS certificates during connection reuse. libcurl supports reuse of established connections for subsequent requests. It does this by keeping a few previous connections "alive" in a connection pool so that a subsequent request that can use one of them instead of creating a new connection will do so.
When using a client certificate for a connection that was then put into the connection pool, that connection could then wrongly get reused in a subsequent request to that same server that either didn't use a client certificate at all or that asked to use a different client certificate thus trying to tell the user that it is a different entity.
This mistakenly using the wrong connection could of course lead to applications sending requests to the wrong realms of the server using authentication that it wasn't supposed to have for those operations.
Install update from vendor's website.
Vulnerable software versionscurl (Alpine package): 7.49.1-r0 - 7.50.0-r0
External linkshttp://git.alpinelinux.org/aports/commit/?id=e57c1f8b95e9a6aecc75e9eaae6c7bf9e259adb6
http://git.alpinelinux.org/aports/commit/?id=7079fe21530ae1c8147925d8b591131b786ab2e9
http://git.alpinelinux.org/aports/commit/?id=619d9f8608068fab555a9a54e6154eb798eb5c2c
http://git.alpinelinux.org/aports/commit/?id=39696e7a1a7079578ea07cb9514fd0c50105340e
http://git.alpinelinux.org/aports/commit/?id=0b5317d5717ad95fbe3c5737438b3f62f5457f61
http://git.alpinelinux.org/aports/commit/?id=773b3cce8cf0ef9f65aa00ac6985aaba3f582b2c
http://git.alpinelinux.org/aports/commit/?id=e2a41181980948dc15f6b20a9b6980444f9f73df
http://git.alpinelinux.org/aports/commit/?id=4bdd777b8634c3c2ef8d4bb6254f22cea78b46d6
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
