CVE-2023-49284
published 2023-12-05CVE-2023-49284: fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family. fish shell uses certain Unicode non-characters internally…
PriorityP428medium6.6CVSS 3.1
AVLACLPRLUIRSUCHINAH
EPSS
0.47%
38.6th percentile
fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family. fish shell uses certain Unicode non-characters internally for marking wildcards and expansions. It will incorrectly allow these markers to be read on command substitution output, rather than transforming them into a safe internal representation. While this may cause unexpected behavior with direct input (for example, echo \UFDD2HOME has the same output as echo $HOME), this may become a minor security problem if the output is being fed from an external program into a command substitution where this output may not be expected. This design flaw was introduced in very early versions of fish, predating the version control system, and is thought to be present in every version of fish released in the last 15 years or more, although with different characters. Code execution does not appear to be possible, but denial of service (through large brace expansion) or information disclosure (such as variable expansion) is potentially possible under certain circumstances. fish shell 3.6.2 has been released to correct this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | fish | < fish 3.6.0-3.1+deb12u1 (bookworm) | fish 3.6.0-3.1+deb12u1 (bookworm) |
| fish-shell | fish-shell | < 3.6.2 | 3.6.2 |
| fishshell | fish | < 3.6.2 | 3.6.2 |
| fishshell | fish | >= 0 < 3.6.0-3.1+deb12u1 | 3.6.0-3.1+deb12u1 |
| fishshell | fish | >= 0 < 3.6.4-1 | 3.6.4-1 |
| fishshell | fish | >= 0 < 3.6.4-1 | 3.6.4-1 |
| msrc | cbl2_fish_3.6.2-1_on_cbl_mariner_2.0 | — | — |
CVSS provenance
nvdv3.16.6MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:H
osv6.6MEDIUM
vendor_msrc6.6MEDIUM
vendor_debian3.9LOW
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Microsoft
Command substitution output can trigger shell expansion in fish shell
vendor_msrc·2023-12-12·CVSS 6.6
CVE-2023-49284 [LOW] CWE-436 Command substitution output can trigger shell expansion in fish shell
Command substitution output can trigger shell expansion in fish shell
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
GitHub_M: GitHub_M
Customer Action Required: Yes
Remediation: CBL-Mariner Releases
Refe
Debian
CVE-2023-49284: fish - fish is a smart and user-friendly command line shell for macOS, Linux, and the r...
vendor_debian·2023·CVSS 3.9
CVE-2023-49284 [LOW] CVE-2023-49284: fish - fish is a smart and user-friendly command line shell for macOS, Linux, and the r...
fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family. fish shell uses certain Unicode non-characters internally for marking wildcards and expansions. It will incorrectly allow these markers to be read on command substitution output, rather than transforming them into a safe internal representation. While this may cause unexpected behavior with direct input (for example, echo \UFDD2HOME has the same output as echo $HOME), this may become a minor security problem if the output is being fed from an external program into a command substitution where this output may not be expected. This design flaw was introduced in very early versions of fish, predating the version control system, and is thought to be present in every version of fish released in th
OSV
CVE-2023-49284: fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family
osv·2023-12-05·CVSS 6.6
CVE-2023-49284 [MEDIUM] CVE-2023-49284: fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family
fish is a smart and user-friendly command line shell for macOS, Linux, and the rest of the family. fish shell uses certain Unicode non-characters internally for marking wildcards and expansions. It will incorrectly allow these markers to be read on command substitution output, rather than transforming them into a safe internal representation. While this may cause unexpected behavior with direct input (for example, echo \UFDD2HOME has the same output as echo $HOME), this may become a minor security problem if the output is being fed from an external program into a command substitution where this output may not be expected. This design flaw was introduced in very early versions of fish, predating the version control system, and is thought to be present in every version of fish released in th
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
http://www.openwall.com/lists/oss-security/2023/12/08/1https://github.com/fish-shell/fish-shell/commit/09986f5563e31e2c900a606438f1d60d008f3a14https://github.com/fish-shell/fish-shell/security/advisories/GHSA-2j9r-pm96-wp4fhttp://www.openwall.com/lists/oss-security/2023/12/08/1https://github.com/fish-shell/fish-shell/commit/09986f5563e31e2c900a606438f1d60d008f3a14https://github.com/fish-shell/fish-shell/security/advisories/GHSA-2j9r-pm96-wp4f
2023-12-05
Published