Explain CVE-2020-1935
In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.
Affected Products: Apache Tomcat
References: [{'name': '[tomcat-announce] 20200224 [SECURITY] CVE-2020-1935 HTTP Request Smuggling', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E'}, {'name': '[debian-lts-announce] 20200304 [SECURITY] [DLA 2133-1] tomcat7 security update', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html'}, {'name': 'openSUSE-SU-2020:0345', 'tags': ['vendor-advisory', 'x_refsource_SUSE'], 'url': 'http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html'}, {'name': '[tomee-commits] 20200320 [jira] [Created] (TOMEE-2790) TomEE plus(7.0.7) is affected by CVE-2020-1935 & CVE-2019-17569 vulnerabilities', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743%40%3Ccommits.tomee.apache.org%3E'}, {'name': '[tomee-commits] 20200323 [jira] [Commented] (TOMEE-2790) TomEE plus(7.0.7) is affected by CVE-2020-1935 & CVE-2019-17569 vulnerabilities', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3E'}, {'name': 'DSA-4673', 'tags': ['vendor-advisory', 'x_refsource_DEBIAN'], 'url': 'https://www.debian.org/security/2020/dsa-4673'}, {'name': 'DSA-4680', 'tags': ['vendor-advisory', 'x_refsource_DEBIAN'], 'url': 'https://www.debian.org/security/2020/dsa-4680'}, {'name': '[debian-lts-announce] 20200528 [SECURITY] [DLA 2209-1] tomcat8 security update', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html'}, {'tags': ['x_refsource_MISC'], 'url': 'https://www.oracle.com/security-alerts/cpujul2020.html'}, {'tags': ['x_refsource_CONFIRM'], 'url': 'https://security.netapp.com/advisory/ntap-20200327-0005/'}, {'name': '[tomcat-users] 20200724 CVE-2020-1935', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75%40%3Cusers.tomcat.apache.org%3E'}, {'name': '[tomcat-users] 20200724 Re: CVE-2020-1935', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3E'}, {'name': '[tomcat-users] 20200724 RE: CVE-2020-1935', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18%40%3Cusers.tomcat.apache.org%3E'}, {'name': '[tomcat-users] 20200726 Re: CVE-2020-1935', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7%40%3Cusers.tomcat.apache.org%3E'}, {'name': '[tomcat-users] 20200727 RE: CVE-2020-1935', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1%40%3Cusers.tomcat.apache.org%3E'}, {'name': 'USN-4448-1', 'tags': ['vendor-advisory', 'x_refsource_UBUNTU'], 'url': 'https://usn.ubuntu.com/4448-1/'}, {'tags': ['x_refsource_MISC'], 'url': 'https://www.oracle.com/security-alerts/cpuoct2020.html'}, {'tags': ['x_refsource_MISC'], 'url': 'https://www.oracle.com/security-alerts/cpujan2021.html'}, {'name': '[tomcat-dev] 20210428 [Bug 65272] Problems proccessing HTTP request without CR in last versions', 'tags': ['mailing-list', 'x_refsource_MLIST'], 'url': 'https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6%40%3Cdev.tomcat.apache.org%3E'}]
CVE State: PUBLISHED