tomcat: Mishandling of Transfer-Encoding header allows for HTTP request smuggling
Published Feb 24, 2020
4.8
MEDIUMCVSS 3.1
EPSS 9.39%
Description
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
-
- Version 7.0.0 to 7.0.99StatusaffectedConstraints-
- Version 8.5.0 to 8.5.50StatusaffectedConstraints-
- Version Apache Tomcat 9.0.0.M1 to 9.0.30StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Apache | Apache Tomcat | n/a |
|
Configuration 1
- ≥ 7.0.0 · ≤ 7.0.99
- ≥ 8.5.0 · ≤ 8.5.50
- ≥ 9.0.0 · ≤ 9.0.30
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
- 9.0.0
Configuration 2
- 8.0
- 9.0
- 10.0
Configuration 3
- 16.04
Configuration 5
- n/a
- ≥ 3.0.0 · ≤ 3.1.3
Configuration 6
- 6.2.1.0
- 9.3.3
- 9.3.5
- 9.3.6
- 8.1.1
- 8.2.0
- 8.2.1
- 10.0.1.4.0
- 1.0.1.2
- 7.3.3
- 4.2.0
- 4.2.1
- 11.1.2.4
- ≥ 17.1 · ≤ 17.3
- ≥ 4.0.0 · ≤ 4.0.12
- ≥ 8.0.0 · ≤ 8.0.20
- 15.0
- ≤ 20.5
- 6.3.7
- 12.2.0.1
- 18c
- 19c
No data.
Red Hat Enterprise Linux 7
tomcat-0:7.0.76-16.el7_9
Fixed · RHSA-2020:5020
Red Hat Enterprise Linux 7.6 Extended Update Support
tomcat-0:7.0.76-11.el7_6
Fixed · RHSA-2021:0882
Red Hat Enterprise Linux 7.7 Extended Update Support
tomcat-0:7.0.76-12.el7_7
Fixed · RHSA-2021:1030
Red Hat Enterprise Linux 8
pki-core:10.6-8030020200911215836.5ff1562f
Fixed · RHSA-2020:4847
Red Hat Enterprise Linux 8
pki-deps:10.6-8030020200527165326.30b713e6
Fixed · RHSA-2020:4847
Red Hat Fuse 7.9
tomcat
Fixed · RHSA-2021:3140
Red Hat JBoss Web Server (JWS) 5.3
tomcat
Fixed · RHSA-2020:1521
Red Hat JBoss Web Server 3 for RHEL 6
tomcat7-0:7.0.70-41.ep7.el6
Fixed · RHSA-2020:3303
Red Hat JBoss Web Server 3 for RHEL 6
tomcat8-0:8.0.36-45.ep7.el6
Fixed · RHSA-2020:3303
Red Hat JBoss Web Server 3 for RHEL 7
tomcat7-0:7.0.70-41.ep7.el7
Fixed · RHSA-2020:3303
Red Hat JBoss Web Server 3 for RHEL 7
tomcat8-0:8.0.36-45.ep7.el7
Fixed · RHSA-2020:3303
Red Hat JBoss Web Server 3.1
tomcat
Fixed · RHSA-2020:3305
Red Hat JBoss Web Server 5.3 on RHEL 6
jws5-tomcat-0:9.0.30-3.redhat_4.1.el6jws
Fixed · RHSA-2020:1520
Red Hat JBoss Web Server 5.3 on RHEL 6
jws5-tomcat-native-0:1.2.23-4.redhat_4.el6jws
Fixed · RHSA-2020:1520
Red Hat JBoss Web Server 5.3 on RHEL 7
jws5-tomcat-0:9.0.30-3.redhat_4.1.el7jws
Fixed · RHSA-2020:1520
Red Hat JBoss Web Server 5.3 on RHEL 7
jws5-tomcat-native-0:1.2.23-4.redhat_4.el7jws
Fixed · RHSA-2020:1520
Red Hat JBoss Web Server 5.3 on RHEL 8
jws5-tomcat-0:9.0.30-3.redhat_4.1.el8jws
Fixed · RHSA-2020:1520
Red Hat JBoss Web Server 5.3 on RHEL 8
jws5-tomcat-native-0:1.2.23-4.redhat_4.el8jws
Fixed · RHSA-2020:1520
Red Hat Runtimes Spring Boot 2.1.13
tomcat
Fixed · RHSA-2020:2367
Red Hat Decision Manager 7
tomcat
Not affected
Red Hat Enterprise Linux 5
tomcat5
Out of support scope
Red Hat Enterprise Linux 6
tomcat6
Out of support scope
Red Hat JBoss Enterprise Application Platform 6
jbossweb
Out of support scope
Red Hat JBoss Fuse 6
tomcat
Out of support scope
Red Hat OpenStack Platform 10 (Newton)
opendaylight
Out of support scope
Red Hat OpenStack Platform 13 (Queens)
opendaylight
Will not fix
Red Hat Process Automation 7
tomcat
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | tomcat-0:7.0.76-16.el7_9 | Fixed | RHSA-2020:5020 |
| Red Hat Enterprise Linux 7.6 Extended Update Support | tomcat-0:7.0.76-11.el7_6 | Fixed | RHSA-2021:0882 |
| Red Hat Enterprise Linux 7.7 Extended Update Support | tomcat-0:7.0.76-12.el7_7 | Fixed | RHSA-2021:1030 |
| Red Hat Enterprise Linux 8 | pki-core:10.6-8030020200911215836.5ff1562f | Fixed | RHSA-2020:4847 |
| Red Hat Enterprise Linux 8 | pki-deps:10.6-8030020200527165326.30b713e6 | Fixed | RHSA-2020:4847 |
| Red Hat Fuse 7.9 | tomcat | Fixed | RHSA-2021:3140 |
| Red Hat JBoss Web Server (JWS) 5.3 | tomcat | Fixed | RHSA-2020:1521 |
| Red Hat JBoss Web Server 3 for RHEL 6 | tomcat7-0:7.0.70-41.ep7.el6 | Fixed | RHSA-2020:3303 |
| Red Hat JBoss Web Server 3 for RHEL 6 | tomcat8-0:8.0.36-45.ep7.el6 | Fixed | RHSA-2020:3303 |
| Red Hat JBoss Web Server 3 for RHEL 7 | tomcat7-0:7.0.70-41.ep7.el7 | Fixed | RHSA-2020:3303 |
| Red Hat JBoss Web Server 3 for RHEL 7 | tomcat8-0:8.0.36-45.ep7.el7 | Fixed | RHSA-2020:3303 |
| Red Hat JBoss Web Server 3.1 | tomcat | Fixed | RHSA-2020:3305 |
| Red Hat JBoss Web Server 5.3 on RHEL 6 | jws5-tomcat-0:9.0.30-3.redhat_4.1.el6jws | Fixed | RHSA-2020:1520 |
| Red Hat JBoss Web Server 5.3 on RHEL 6 | jws5-tomcat-native-0:1.2.23-4.redhat_4.el6jws | Fixed | RHSA-2020:1520 |
| Red Hat JBoss Web Server 5.3 on RHEL 7 | jws5-tomcat-0:9.0.30-3.redhat_4.1.el7jws | Fixed | RHSA-2020:1520 |
| Red Hat JBoss Web Server 5.3 on RHEL 7 | jws5-tomcat-native-0:1.2.23-4.redhat_4.el7jws | Fixed | RHSA-2020:1520 |
| Red Hat JBoss Web Server 5.3 on RHEL 8 | jws5-tomcat-0:9.0.30-3.redhat_4.1.el8jws | Fixed | RHSA-2020:1520 |
| Red Hat JBoss Web Server 5.3 on RHEL 8 | jws5-tomcat-native-0:1.2.23-4.redhat_4.el8jws | Fixed | RHSA-2020:1520 |
| Red Hat Runtimes Spring Boot 2.1.13 | tomcat | Fixed | RHSA-2020:2367 |
| Red Hat Decision Manager 7 | tomcat | Not affected | n/a |
| Red Hat Enterprise Linux 5 | tomcat5 | Out of support scope | n/a |
| Red Hat Enterprise Linux 6 | tomcat6 | Out of support scope | n/a |
| Red Hat JBoss Enterprise Application Platform 6 | jbossweb | Out of support scope | n/a |
| Red Hat JBoss Fuse 6 | tomcat | Out of support scope | n/a |
| Red Hat OpenStack Platform 10 (Newton) | opendaylight | Out of support scope | n/a |
| Red Hat OpenStack Platform 13 (Queens) | opendaylight | Will not fix | n/a |
| Red Hat Process Automation 7 | tomcat | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
OpenDaylight in Red Hat OpenStack 10 & 13 was in technical preview status, because of this no fixes will be released for it. In Red Hat Satellite 6, Candlepin is using Tomcat to provide a REST API, and has been found to be vulnerable to the flaw. However, it is currently believed that no useful attacks can be carried over.
Red Hat mitigation
Workaround for Red Hat Satellite 6 is to add iptables rule to deny TCP requests of Tomcat that are not originating from the Satellite. For other Red Hat products, either mitigation isn't available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
1 other source (Red Hat) ▾
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (19 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 9.39% (0.09386) | 95.26th | v5 (v2026.06.15) |
| Jun 15, 2026 | 9.39% (0.09386) | 94.75th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.04% (0.01040) | 75.44th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.56% (0.02558) | 75.79th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.04% (0.01040) | 75.90th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.24% (0.00240) | 62.89th | v3 (v2023.03.01) |
| Jan 31, 2024 | 0.24% (0.00240) | 62.14th | v3 (v2023.03.01) |
| Jan 15, 2024 | 0.21% (0.00210) | 58.88th | v3 (v2023.03.01) |
| Dec 29, 2023 | 0.20% (0.00199) | 57.73th | v3 (v2023.03.01) |
| Nov 8, 2023 | 0.18% (0.00183) | 55.40th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.19% (0.00194) | 55.38th | v3 (v2023.03.01) |
| Mar 6, 2023 | 7.77% (0.07767) | 93.09th | v2 (v2022.01.01) |
| Apr 1, 2022 | 7.77% (0.07767) | 92.44th | v2 (v2022.01.01) |
| Feb 4, 2022 | 44.26% (0.44262) | 97.72th | v2 (v2022.01.01) |
| Feb 3, 2022 | 36.44% (0.36436) | 98.05th | v1 |
| Jan 6, 2022 | 36.44% (0.36436) | 98.03th | v1 |
| Sep 1, 2021 | 11.33% (0.11329) | 95.51th | v1 |
| Apr 29, 2021 | 11.33% (0.11329) | 0.00th | v1 |
| Apr 14, 2021 | 10.82% (0.10820) | 0.00th | v1 |
References (35)
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html vendor-advisoryx_refsource_SUSEBroken LinkMailing ListThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2020-1935 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1806835 Issue Tracking
- https://github.com/advisories/GHSA-qxf4-chvg-4r8r Advisory
- https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E mailing-listx_refsource_MLISTMailing ListVendor Advisory
- https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75%40%3Cusers.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75@%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919@%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1%40%3Cusers.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1@%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6%40%3Cdev.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6@%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7%40%3Cusers.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7@%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743%40%3Ccommits.tomee.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18%40%3Cusers.tomcat.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18@%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2020-1935
- https://security.netapp.com/advisory/ntap-20200327-0005/ x_refsource_CONFIRMThird Party Advisory
- https://tomcat.apache.org/security-7.html#Fixed_in_Apache_Tomcat_7.0.100
- https://tomcat.apache.org/security-8.html#Fixed_in_Apache_Tomcat_8.5.51
- https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.31
- https://usn.ubuntu.com/4448-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2020-1935
- https://www.debian.org/security/2020/dsa-4673 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.debian.org/security/2020/dsa-4680 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html x_refsource_MISCThird Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.html x_refsource_MISCThird Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html x_refsource_MISCThird Party Advisory
Change history (0)
No recorded changes yet.