CVE-2021-36740: debian debian_linux HTTP Request/Response Smuggling
CVSS: 6.5v3.1MediumModified
AliasesALPINE-CVE-2021-36740MGASA-2021-0387RHSA-2021:2988RHSA-2021:2993UBUNTU-CVE-2021-36740DEBIAN-CVE-2021-36740
Published 14-07-2021Last modified 04-08-2024
Vulnerability summary
CVE-2021-36740 is a medium (CVSS 6.5) HTTP Request/Response Smuggling vulnerability in debian debian_linux. EPSS estimates a 1.60% chance of exploitation in the next 30 days, higher than 75.4% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
1.60%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 14-07-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8.
CVSS metrics
6 scores · 5 sources · 2 versionsMedium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NSources5 sources · 6.5–8.1
- OSV · AlpineEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- OSV · Red hatEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Medium 6.4Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.60%
Chance of exploitation in the next 30 days
Percentile
75%
Versus all other CVEs
30-day change
0.00 pp
From 1.60% on 19-09-2026
19-09-202619-10-2026
EPSS score1.60%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Redhat12 products
- rh-varnish6-varnish< 0:6.0.8-2.el7
- rh-varnish6-varnish-devel< 0:6.0.8-2.el7
- rh-varnish6-varnish-docs< 0:6.0.8-2.el7
- rh-varnish6-varnish-libs< 0:6.0.8-2.el7
- rh-varnish6-varnish-modules< 0:0.15.0-7.el7
Debian2 products
- varnish< 6.5.2-1
- debian_linuxEOL10.0 | 11.0
Alpine1 product
- varnish< 6.5.2-r0 | < 6.6.1-r0
Fedoraproject1 product
- fedoraEOL33 | 34
Mageia1 product
- varnish< 6.5.1-1.1.mga8
Ubuntu1 product
- varnish< 6.2.1-2ubuntu0.1
Varnish_cache_project1 product
- varnish_cache≥ 5.0.0, ≤ 5.2.1 | ≥ 6.1.0, ≤ 6.6.0
Varnish-cache1 product
- varnish_cache≥ 6.0.0, < 6.0.8 | 6.0.8:r1 | 6.0.8:r2
Varnish-software1 product
- varnish_cache≥ 6.0.0, ≤ 6.0.5 | ≥ 6.0.0, ≤ 6.0.7
9 vendors · 21 products
References
23 links- github.com/varnishcache/varnish-cache/commit/9be22198e258d0e7a5c41f4291792214a29405cfX Refsource MISCREPORTPatchThird Party Advisory
- github.com/varnishcache/varnish-cache/commit/82b0a629f60136e76112c6f2c6372cce77b683beX Refsource MISCREPORTPatchThird Party Advisory
